I did a search... could not find any solutions...

I have a 2001 a4 1.8t quattro standard trans with 95k
did timing belt water pump and all that at 80k

situation is as follows... drove my car home one night... ran fine...

start it up the next day (it was about 40* out) and a block from my house, CEL flashes and I have a bad misfire

go back home and locate that it is the #3 cyl coil pack is not firing

I borrow my roommates coil pack and now cyl #1 misfires

borrow another coil and then cyl #2 misfires

borrow another then cyl #4 misfires

so i borrow all four of his coil packs and all is well

I also pull my plugs to look at them and #3 is rank of gas and obviously was not firing for a bit

I drive my car a few hundred miles on borrowed coil packs while i wait for a new set

I get new set and install them... all seems well

After a moderate test drive of the new parts, i am satisfied, park the car for about an hour and then depart...

identical misfire symptom halfway to my friends house... i park it at their house, return the next day and the car runs fine on the short drive home.

next day i roll the dice and drive the car and it does fine on the trip to the dentist. immediately after starting the car(it sat for 20-30mins) it is missing.

I limp it to an autozone and have codes pulled... i have seven faults, a rear o2 sensor that has been there forever and catalyst damaging mis codes and random mis codes on all cylinders

i buy new plugs and a CTS and start limping home... after about a mile it starts to run fine... then it starts missing again... then after missing for a mile it runs fine for the last mile and it did this dance for a total of 4 miles...


I lost the actual DTC's and do not wanna drive the car since my cat is prolly half melted by now anyways...


Cliffs: Car missfired, borrowed coil packs worked well for a week, new coil packs work well for a day and car misfires some more after plugs, coils and CTS all replaced
I have a o2 sensor, but it is a front one, and i have a spare rear one, but the conn is different than mine, can i simply splice a conn onto one of them or return the new front o2 in exchange for a rear and be done with that?


Would really appreciate any help... i don't have a scanner or vag-com so getting you guys current DTC's does not looks promising...


thanks in advance and sorry for the length

 

anyone?

 

I'd guess that your cat is clogged. I have no explanation for the run around with the coil packs, but if they are all new, and you have no ICM, and no MAF faults, I don't know what else it could be. A bad head gasket could cause misfires but you'd have other symptoms with that and they are never an issue w/ 1.8T's anyways.

 

i think i might have a cat sitting in my garage... i suppose i could try swapping it out while i contemplate what else it could be...

i forgot to mention that i had a low coolant message, so i added water... but the oil on the dipstick was normal looking so i doubt it is a head gasket

 

I suppose i should mention that while diagnosing the issue to narrow it down to a coil or CTS i let the car idle and warm up... when i went out to check on it after 5 minutes or more, the cat was glowing very brightly...

just kinda weird because the car ran great for about a week or two after this and now it appears to be fubar