[Kojack150]

ok, owner of a 1996 ford mustang with a 3.8 V6 engine at 75,500 miles so far, heres a quick rundown.

i did a tune-up a almost a week ago cause that 3,000 mile mark was approaching and she was burning a little more gas than she should, so i changed the oil, air filter, PCV valve, fuel filter and transmission fluid (its a auto) and it was doing fine until about 2 days later, the condition started to deteriorate.

i noticed that at 100mph on my way home from work, the engine was running at 4,000rpm, and i know this car well enough to know it never switched into 4th gear, remained in 3rd. so i came off the highway (my my exit anyway), and pulled to the side. nothing was leaking out nor did anything looked abnormal but i began feeling and hearing a rough idle coming out the car. couldnt figure out exactly what it was (being 1am), but the car started losing power.

6 months ago, i had the engine oil, PCV valve, fuel filter, air filter, spark plugs, spark plug wires, IAT sensor, one fuel injector for cylinder 6 (thing was expensive as hell at the time for each) and coil pack swapped out and the MAF cleaned out because of a similiar instance of this loss of power.

now the OBD-II scanner showed me codes P0305, P0303 and P0174. to play it safe, i decided to swap out all the spark plugs for new ones and noticed 1 plug out of cylinder 4 was coated in black, but couldnt tell if it was carbon deposits or leaking oil. I ran 2 tests to pinpoint the exact cause for the misfire and discovered that while the injectors were still doing their job via the sound test, i took unplugged each spark plug wire and noticed no further dips in the RPM when the wires to cylinder 1 and 4 were removed. the sparks are getting their voltage but a second time i removed the plug, i caught them wet with oil.

now i did a quick swap with the valve stem seals on cyl 1 and 4 and it barely smoothen out. from what i read on other topics here, im trying to rule out the O2 sensors but i may got no choice. P0174 is like screaming out at me, i know it lol

if anyone can help me out, where else do i look? what else should i tinker with?

[03Stangr]

Originally Posted by Kojack150

ok, owner of a 1996 ford mustang with a 3.8 V6 engine at 75,500 miles so far, heres a quick rundown.

i did a tune-up a almost a week ago cause that 3,000 mile mark was approaching and she was burning a little more gas than she should, so i changed the oil, air filter, PCV valve, fuel filter and transmission fluid (its a auto) and it was doing fine until about 2 days later, the condition started to deteriorate.

i noticed that at 100mph on my way home from work, the engine was running at 4,000rpm, and i know this car well enough to know it never switched into 4th gear, remained in 3rd. so i came off the highway (my my exit anyway), and pulled to the side. nothing was leaking out nor did anything looked abnormal but i began feeling and hearing a rough idle coming out the car. couldnt figure out exactly what it was (being 1am), but the car started losing power.

6 months ago, i had the engine oil, PCV valve, fuel filter, air filter, spark plugs, spark plug wires, IAT sensor, one fuel injector for cylinder 6 (thing was expensive as hell at the time for each) and coil pack swapped out and the MAF cleaned out because of a similiar instance of this loss of power.

now the OBD-II scanner showed me codes P0305, P0303 and P0174. to play it safe, i decided to swap out all the spark plugs for new ones and noticed 1 plug out of cylinder 4 was coated in black, but couldnt tell if it was carbon deposits or leaking oil. I ran 2 tests to pinpoint the exact cause for the misfire and discovered that while the injectors were still doing their job via the sound test, i took unplugged each spark plug wire and noticed no further dips in the RPM when the wires to cylinder 1 and 4 were removed. the sparks are getting their voltage but a second time i removed the plug, i caught them wet with oil.

now i did a quick swap with the valve stem seals on cyl 1 and 4 and it barely smoothen out. from what i read on other topics here, im trying to rule out the O2 sensors but i may got no choice. P0174 is like screaming out at me, i know it lol

if anyone can help me out, where else do i look? what else should i tinker with?

First, why wasn't your tranny going into overdrive ?, Look at the tranny fluid and make sure it's not a brown color, if it is, change your tranny fluid and filter. 2nd theirs rev and speed limiters set unless you get a tuner and disable it, 3rd have you done all the required maint. on it at the recommended intervals ?
Try doing a compression check on all 6 cylinders. All of the cylinders should be about the same. It's okay if the compression is a little low as long as they are all just a little low. If one or two are really low, but the rest are not, then you have a problem. Any blue smoke coming out of the rear pipes ? Replace the coil and wires as well if you have never done that. Don't just replace the ones that are not good, replace the whole set at the same time. Sounds like your car needs quite a bit checked out. I'd get a tuner if I were you so you could trouble shoot codes and it will give your car the best tune possible. If you can't swing the tuner, get a scanner that is just used to troubleshoot trouble codes.
My .02 worth