SES Light Hell

gozer61

New Member
Oct 7, 2003
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I bought a used 2002 GT convertible with 16K miles about a month ago from a dealer completely stock. Added the C&L 85mm MAF housing and K&N filter combo, then had the Steeda underdrive pulleys installed (bought from stangnet here, and yes, I believe they're the correct ones). I've disconnected the battery four times, each time for a minimum of 15 minutes to reset the computer since the mods were installed.

Since then, I have been getting an intermittent engine misfire according to the computer codes.

I pulled the MAF and used a spray electronic degreaser to clean the wires in case any of the air filter's oil was somehow fouling them.

I've taken it to the dealer twice now. The first time, they cleared the computer and said that they don't recommend underdrive pulleys. The second time, I had them check the torque on the balancer pulley as I've read that an incorrect setting can cause misfiring. The torque is correct according to the mechanic. They did come up with some Ford technical bulletin that states that underdrive pulleys do cause sporadic engine misfire. Big surprise there.

I've driven the car a total of 10 miles since getting it back from the dealer the second time. The SES light is back on full-time, and this morning, it blinked at me two different times, then settled back to a steady burn. I could feel the engine's rough response when the light was blinking, so I'm guessing it was actively misfiring at those times, then smoothed out when the misfiring stopped.

From what I've read and been told, both of these mods are pretty well tested and very safe and stable. My experience with them has been lousy to date. I really like the extra kick I get from the throttle, but I am not going to drive it forever with the engine misfire. In fact, the mustang's in the driveway until I can figure something out to try next. If I have to, I'll remove the pulleys and the MAF/Filter upgrade. However, I'm hoping someone out there can suggest something else to try to get rid of this problem once and for all without sacrificing the mods.

I have yet to re-install the original air filter and MAF housing. Why? One of the torx bolts was thread-lok-ed into the brass insert in the plastic housing and pulled the insert out of the housing when I removed it. Of course I dropped the insert and it rolled away somewhere where I can't find it. I'm working on a replacement insert, but they're a bitch to get in the correct size (Metric??? Isn't this an American car?). If/when I can secure the MAF with both bolts, I'll try re-installing the stock components.

What's the concensus out there? Do some cars simply just not like these mods? Do I need some undocumented computer setting change?

Thanks for any help y'all can provide.
 
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Answers as far as I know them:

1. The dealer said the misfire code was not specific to any single cylinder, but a "generic" misfire code. I don't know what the numeric value is/was. I'll try Pep Boys to see if they can pull the latest one.

2. Yes, factory bolt was used, not the one you use to install the pulley initially. I haven't had the water pump or the alternator pulley checked, and I'm not sure what the trigger wheel is, but I'll find out.

3. Shell/Texaco premium grade gasoline.
 
Not sure the larger MAF is good for your set-up. From my experience UDP may cause a misfire but usually a specific cylinder will show up in the code. But I don't know why either would be throwing misfire codes especially during regular driving. Most UDP only show misfire at start-up. Check your coils (HOLY CRAP...a freakin yellow jacket just landed on my desk).....OK now. Check your coils and plugs to see if they are ok.
 
I'll have to burn through the current tank but will try the regular unleaded. I thought the owner's manual recommended premium? I'll also check the ignition system as well as get the latest code pulled to see if it makes a specific suggestion as to the problem.

When I measured the stock MAF housing, it came out to 75mm. I'm not sure that a 10mm difference between it and the C&L housing is worth it to me as I rarely run the engine at high revs (i.e. near the redline). I might be just as happy with the stock assembly and a K&N replacement filter. At least then I'd know that the hot engine compartment air was not a factor as the heat shield the kit came with doesn't completely enclose the filter as the stock assembly does. Still, if I can get it to work, every little bit of extra kick helps!

Thanks, guys! Keep those cards and letters coming.
 
Your owners manual should recommend 87 octane. I ran it on my GT when I had it with no problems.

As far as the MAF goes, speaking from experience, upgrading it on a 2002 is a waste of money in my opinion. The stock MAF on the '02 is 80mm by the way. The stock intake system actually flows pretty good believe it or not. The restriction is in the heads.
 
sounds like something in the crank pulley still man. i know you had the torque checked, but did whoever did the install put sealer in the ketnotch area? I know that can lead to some big uh oh's if not sealed correctly. If you had a mechanic look at it, I would hope that they would notice something like that, but if the pulley wasnt taken off I doubt he would.
 
yup, checked with the installer and he swears he gooped up the keynotch well.

i get an error trying to access the web page mentioned. up pops an odbc access driver error code and "too many clients". going to the main page is o.k., but trying to click on anything there results in a variety of errors for me.

thanks for the info, though.

last night, i was extremely lucky. turns out one of the pieces of hardware we buy has the exact brass plastic insert i needed for my stock MAF housing, and it fit perfectly. heated it up with a soldering iron and the plastic melted around it like it was made for that application. i bought a new k&n filter to replace the stock one in the filter housing, then reinstalled the stock filter/MAF assembly. i'm pretty comfortable with this as the difference is only .05mm in the MAF housing diameter between stock and c&l, and the stock housing is both enclosed and forces intake from the fender well. i left the battery disconnected for 45 minutes, then reconnected and went for a test drive. no problems under street and highway driving including hard acceleration and deceleration. the light's still off this morning after driving to work, so i'll just keep my fingers crossed that it might have been something about the c&l rig that was causing the problem. i find that hard to believe, but i guess stranger things have happened.

i'll keep this thread posted.
 
Well, the weekend was uneventful which is good! I drove about 100 miles and used up most of the rest of the tank of premium so I'll fill up with regular unleaded and see if that makes a difference. However, the SES light hasn't yet resurfaced since removing the C&L MAF and reinstalling the stock unit. I'm still keeping my fingers crossed.

By the way, I was able to get to the web page mentioned above this morning. It does state the text of the code, but there's nothing there that says what, if anything, can be done about it.
 
gozer61 said:
Well, the weekend was uneventful which is good! I drove about 100 miles and used up most of the rest of the tank of premium so I'll fill up with regular unleaded and see if that makes a difference. However, the SES light hasn't yet resurfaced since removing the C&L MAF and reinstalling the stock unit. I'm still keeping my fingers crossed.

By the way, I was able to get to the web page mentioned above this morning. It does state the text of the code, but there's nothing there that says what, if anything, can be done about it.
That's why mechanics get the bucks....they know (or are supposed to know) how to diagnose codes. I haven't found a site or text yet that give any fixes for codes. Hopefully you won't have any more misfire problems.
 
I finished the premium and refilled with regular unleaded. Today on the way to work, the damn SES light came back on and the engine ran rough for about a minute. Same old same old. I guess the underdive pulleys come off unless there are any other suggestions. Too bad, though. I guess some cars just don' t like them and mine is one.

At least with the pulleys off, I'll find out if the problem is them or something else. If the problem resurfaces after they come off, at least Ford service will look at it.
 
I made an appointment with a mechanic to remove the pulleys a couple days ago, but later that day, a co-worker hooked me up with a service rep at a local Ford dealership who was willing to examine the car for problems even with the underdrive pulleys attached unlike the dealership where I bought it. The service rep's a chevy man, but his mechanics are mustang enthusiasts who do mods on their own cars. This was good news!

I left the car there overnight and picked it up today. They said that they were able to get a specific cylinder misfire code as well as the generic one, but after examining all coils and plugs, there were no problems indicated there. The hardware looked fine. The invoice shows that they performed the following: EEC diagnosis, DCL display test, Fuel pump pressure test, Injector flow test, a recorder/monitor road test, and the PCM reprogramming, as well as the fuel filter replacement. Since I just replaced the stock air filter with a new K&N last week, they left that alone. If the SES light comes on again, I'll take it back and they'll look at it again.

I feel better taking the vehicle to authorized Ford technicians who also happen to do mods to their own mustangs. They should be able to figure out what's going on if anyone can. I might be able to help me with any other mods I want to do in the future too. We'll see. One thing at a time...

I'll keep everyone posted in the belief that this may help someone else. Let me know if this isn't of any particular value and I'll drop the thread.
 
Well, here's the latest in the saga...

1. It took three days, but the light came on again and occasionally flashed at me indicating more misfiring.

2. Before I could get it back to the shop, we had a torrential downpour one evening, and on my way home, all the power equipment went dead as I was trying to get onto the highway. I had just driven through a huge puddle and the battery light came on while steering and brakes went out. I managed to drive it to the local dealership who again chided me for having underdrive pulleys and telling me that they would not warrantee any more work. Well, being in a bind, I didn't have a lot of choice. As you might have guessed, the car threw the main belt (this happen to anyone else out there or am I just exceptionally lucky?) so I had them check the tensioner and the belt itself. The belt was used but otherwise the same size and length as a new one. A hundred bucks later I had a new belt (probably not needed, but better safe than sorry) and another earful of why I shouldn't use them. The last thing the service rep said to me was that his technician thought that the balancer pulley was not aligned with the others properly. Hmmmm..... Of course, he wouldn't elaborate or do anything about it.

3. The new belt squealed a lot driving to the other dealer. I told them what had happened, told them that the balancer pulley might not be aligned correctly, and they took the mustang in promising to look it over carefully and find the root of the problem. Calling near the end of the day, they found misfire codes for all cylinders but nothing telling them what was going on. I agreed to leave it with them for another day.

4. More driving tests, a fuel line pressure test, and more driving tests, and they were still stumped. They asked for another day to continue checking and I agreed as I have my truck to get around.

5. More driving and diagnostics. Nothing shed any new light on the problem, and, of course, they couldn't get the misfiring to occur while they had the car. I told them to take the underdrive pulleys off and replace the stock ones I had placed in the trunk before I drove down there. It was friday and I wanted to have the car for the weekend. I figured if nothing else, the pulleys could be eliminated as a possible problem source even if the SES light came back on. The only non-stock item would then be the K&N filter in the stock housing I'd put in there last week.

6. I called just before closing to see if the mustang was ready to be picked up and they had some news: while pulling the balancer pulley, guess what bolt they found? Yup, you guessed it: the extended bolt clearly labelled in the pulley installation directions as the one to be used ONLY to pull the new balancer pulley into place so that the original bolt would bite! The paper sticker with the warning NOT to use it permanently was still on the bolt!!!
I was both infuriated and elated. First off, I was mad at the original pulley installer because he specifically told me that he used the correct bolt; that he'd replaced the original as the instructions stated. Clearly he had not. Second, why had none of the technicians noticed the belt squealing and misaligned pulley until just a couple days ago, and why had none of them done anything about that? Third, why, even after I asked people to look specifically into the problem of a misaligned pulley and a squealing belt, was this bolt mistake only found at the last minute, and only because I wanted the original pulleys installed? Why was everyone so willing to assume that the problem was based on electrical problems and only pursue those? Perhaps it was my fault in that I had miscommunicated something.
Long and short is that it doesn't matter why. People make mistakes. Life goes on.

7. When I picked up the mustang, they decided that the K&N filter was NOT a good idea because the MAF was "fouled" with its oil. That's a known condition and a few squirts of a degreaser clears it up. Still, they charged me for a new Ford air filter. They left the underdrive pulleys installed, and I drove off with the original pulleys, the helper bolt, and the instructions with the warning highlighted on the installation instructions safely back in the box, and the K&N filter in a Ford box in the trunk. I was pretty sure that this was the root of my problems and that I would not have any more. I was wrong.

8. I drove for 15 minutes to a restaurant and had dinner. About an hour later, I got in the car, started the engine, began to pull out of the parking lot, and my good friend the SES light came back on, then it started winking at me as if to laugh ("You thought you'd get rid of me????"). Rough running and periodic misfires followed me home. Total bummer.

9. The car goes back to the shop monday. They have some recording device they'll hook up to the computer and hopefully as I drive it and experience problems, it will record some live information that will help them figure out what NOW is happening.

I'm pretty discouraged at this point, but will keep trying to figure out whether or not I just got a lemon... I have yet to remove the underdrive pulleys, so perhaps that's still something that will eliminate the problem.

I'll keep you posted as the saga continues...
 
Latest news:

I spent time at the dealer yesterday. I drove the car on and off the highway and, of course, the problem didn't exhibit. Coasting in 2nd back into the service dropoff area, though, the SES light started flashing. The tech hooked it up to his machine which promptly diagnosed a misfire on cylinder 2 where they've seen it before. They had just replaced that plug but the coil checked out, so it's not the plug or the coil.

Not much was revealed by that test, so they were taking the diagnostic machine apart and putting the computer into the passenger seat to go out and drive it more when I left. I'm not sure what the components are behind the balancer pulley, but there's a magnetic wheel of sorts under there that is intimately involved in timing, and I'm making a wild guess that it or something else in there was damaged by the improperly installed underdrive balancer pulley. So far, that's just a wild guess. If I understood the technician's heavily accented English correctly, he's planning to disassemble that part of the engine if his driving tests don't give him any more info. At least they now know how I drive the vehicle and hopefully won't need me to make it misfire again.

By the way, I keep the engine in the 3 - 4K power band most of the time. I rarely drive on the highway so I really never use fifth gear. I accelerate to 70 in third, then shift to fourth which drops back to 3K. I also downshift below 3K and use the engine to slow the vehicle much more often than applying the brakes. They were apparently much more conservative when test driving the vehicle.

I've told them to reinstall the stock pulleys to eliminate any possibility that it's something to do with them directly now. I don't know if they'll do that or continue with the current setup. Those pulleys are now the only non-stock component on the vehicle (to my knowledge). We'll see what happens next.