Pull the OBDII history?

[Tomtom9401]

Hey guys, i did a search and didnt find anything about this. But i have a 2004 Stang GT 4.6L 5 speed 55k miles. Everything stock minus the catback exhaust and rims. I bought the car a week ago and noticed a day after driving it that a P0420 code came up which according to my scanner, is a catalyst effieciency below bank 1 threshold. I am assuming that this could be a bad o2 sensor, bad cat or possibly an exhaust leak? Where is the o2 sensor at bank 1 located? Also, could there be possibly a more serious problem with the engine of only 55k miles on it? Give me worst case scenario. I have erased the code 2 times with my scanner and it has came back in about a day of moderate driving. My main question is, is it possible for a dealer to pull the history of codes that the car has shot out even with them being erased by a scan tool? The dealer may be more inclined to fix the problem if i could prove that it has had this problem previously. Thanks!

P.S. While i am posting a thread i figure i would ask another question about a strange smell coming from my car. The dealer had recently put new brakes on the car before we bought it, after getting it home we noticed a funny smell coming from the car. We initially thought it was the new brakes wearing in, possibly just cheap brakes that were a little to fat for the calipers, but now it is a week later and i am still smelling it after only driving for 15 miles. I am beginning to wonder, could it possibly be the clutch burning? I dont feel i am perfect at shifting yet but i dont feel that i go incredibly hard on the clutch either. Any suggestions? Thanks again guys.

 

[trinity_gt]

Hey guys, i did a search and didnt find anything about this. But i have a 2004 Stang GT 4.6L 5 speed 55k miles. Everything stock minus the catback exhaust and rims. I bought the car a week ago and noticed a day after driving it that a P0420 code came up which according to my scanner, is a catalyst effieciency below bank 1 threshold. I am assuming that this could be a bad o2 sensor, bad cat or possibly an exhaust leak? Where is the o2 sensor at bank 1 located?

The sensor in question is the rear O2 sensor on the passenger side.

If the car has an aftermarket midpipe you may have your answer there. If the car still has the stock part it's probably a bad sensor.

Also, could there be possibly a more serious problem with the engine of only 55k miles on it?

I'd only consider worst-case scenarios when the simplest things are ruled out

My main question is, is it possible for a dealer to pull the history of codes that the car has shot out even with them being erased by a scan tool?

Nope. The PCM has no such logging and retention. Once erased, codes are gone.

P.S. While i am posting a thread i figure i would ask another question about a strange smell coming from my car. The dealer had recently put new brakes on the car before we bought it, after getting it home we noticed a funny smell coming from the car. We initially thought it was the new brakes wearing in, possibly just cheap brakes that were a little to fat for the calipers, but now it is a week later and i am still smelling it after only driving for 15 miles. I am beginning to wonder, could it possibly be the clutch burning? I dont feel i am perfect at shifting yet but i dont feel that i go incredibly hard on the clutch either. Any suggestions? Thanks again guys.

You might have a dragging brake. Drive the car around the block a couple of times, then gently stop. Get out and try to sense the heat at the hub of each wheel. Be careful because if you do have a dragging brake, it could be quite hot. But if you can touch or at least sense each wheel's hub, you might detect way more heat coming from one wheel.

Do you get the impression the car rolls easily in neutral? When a light turns green and you release the brake pedal on an incline, does the car roll back a bit?

 

[MaxedGT]

It's likely a bad cat.
In Canada Cat's and ecm's are covered by a 7 year 130,000 km warranty. Likely a similar warranty in the states. I'd suggest you go back to the selling dealer and insist they fix it.

 

[MaxedGT]

Click here.
2004 Ford Mustang Warranty - Consumer Guide Automotive
Read the fine print.

 

[Tomtom9401]

The sensor in question is the rear O2 sensor on the passenger side.

If the car has an aftermarket midpipe you may have your answer there. If the car still has the stock part it's probably a bad sensor.



I'd only consider worst-case scenarios when the simplest things are ruled out



Nope. The PCM has no such logging and retention. Once erased, codes are gone.



You might have a dragging brake. Drive the car around the block a couple of times, then gently stop. Get out and try to sense the heat at the hub of each wheel. Be careful because if you do have a dragging brake, it could be quite hot. But if you can touch or at least sense each wheel's hub, you might detect way more heat coming from one wheel.

Do you get the impression the car rolls easily in neutral? When a light turns green and you release the brake pedal on an incline, does the car roll back a bit?

Hey man thanks for the quick reply, i am not sure that it had an aftermarket midpipe, but i havent had it on a lift yet so i am not for certain. If it is a catalytic converter would the vehicle still be under the 8yr 80k mile warranty even with the aftermarket catback exhaust system? About the brakes, i noticed when i drove it to the carwash the other day i sprayed water on the rotor and it just steamed off like nothing. I only tested it on the passenger side but it may also have done the same on the drivers side. When the car is in neutral it does roll back quite a bit especially on a hill, almost had my first wreck being a first time manual driver hehe. But i wouldnt know what to compare it to I.E. before they put the brakes on. Suppose the passenger side brakes are dragging, what would be the cause and fix? Thanks!

 

[Tomtom9401]

Sorry i forgot to mention, but i just had the car inspected right before the light came on, so i am doubting its a cat. I am also curious as to why this o2 sensor would start acting like it is, it only comes on every other day. Its not like it comes back right when i start the car up and rev it. I drive down the highway and back with no problems. Then the next day i go down the highway and it is back. Could i just take out the o2 sensor and clean it? Or would it require a new one?

 

[GDawg]

Take it to a shop and have them put it on a scope to compare the upstream sensor with the downstream sensor. They'll be able to tell if your cat is damaged. Watch your oil usage. They may have used Zinc/Phosphate additives that destroyed your cat and if so, I'm sure the other one is on the way out.

 

[burnthelight88]

It takes about 40 miles once you erase the light for it to come back on in most cases. It's called a drive cycle for emissions purposes. That's why you aren't getting it back right away. Have the sensor tested or just replace it.

I wouldn't think worst case scenario yet, but if you want one, it'd be that you need a new catalytic converter which are a few hundred dollars typically.

 

[nyuk98gt]

Tomtom9401:

Get the front off the ground and spin the tires. If one wheel is hard to turn then the brake is dragging. The +99's do have a bit of a reputation for sticky front caliper problems. Once the fronts are checked, check the rears. If the rear(s) is hard to turn then the e-brake could be dragging (check the cable is not hung up somewhere), or, a caliper might be stuck. The rear pistons need to be rotated and pushed into the caliper. Last thing is that the pads could be thicker than the stockers. Some StangNet-ers have posted that Hawk pads were too thick and caused the front brakes to drag. Stock pads should be fine.

Do you have a buddy with an XCal and a laptop? If so, you can datalog - as much as you want and as many parameters that you want. I don't know if the Diablo Predator offers the same datalogging capabilities but that might be another option. Without data, it will be difficult for you to pinpoint the problem.

GL,

Chris

 

[Mustang5L5]

Bad cats smell like sulfur..or rotten eggs. If thats not the smell, then it's not bad cats.


As for brake drag, the common reason is not lubricating the slide pins, or a seized slide pin....especially the rear caliper. The pin sticks, doesn't allow the caliper to center, and generally presses one pad against the face of the rotor all the time heating it up.

Also, does your obd2 scanner have live data recording ability if so, pull it up and monitor the o2 sensors.

 

[Tomtom9401]

Bad cats smell like sulfur..or rotten eggs. If thats not the smell, then it's not bad cats.


As for brake drag, the common reason is not lubricating the slide pins, or a seized slide pin....especially the rear caliper. The pin sticks, doesn't allow the caliper to center, and generally presses one pad against the face of the rotor all the time heating it up.

Also, does your obd2 scanner have live data recording ability if so, pull it up and monitor the o2 sensors.

Thanks everyone for the responses. I havnet noticed such a smell so im assuming its not the cats. But my scanner also has the live data recording which i can monitor the o2 sensors, and from what i noticed both the left and right side o2 sensors are putting out close to the same readings. Could this mean it could be a small exhaust leak that is coming on under higher rpms? Guess i might be taking it back to the dealer if the code comes back again.