earthbound741

ok ok,
so just wanted to share this weird thing i been having with my 99. uhh. i got the car about 2 months ago. it had a code on the ecm, p0420... it also did really weird idle... so after i drove it about 30 miles, all went away. (dust from the shop i suppose since it had work done on the front end). ok so after a while of driving, about 3 weeks in, i get the check engine code again. P0420 and a transmission 3rd clutch pressure some thing something... it was rainy then and as soon as it got warm again, the codes went away. ok so now about 2 weeks later, or about 4 weeks ago, i get the same codes again (p0420 and tranny). so im worried AGAIN . just today, i decided to put in mobile gasoline instead of the shell i been getting a lot of times, and codes are gone! you guys think shell gas is making this happen? i mean i would understand the p0420, but how can the tranny be a part of this. or is it just a coincidence?

heyitsvu

iTrader: (1)

A code P0420 may mean that one or more of the following has happened:

* Leaded fuel was used where unleaded was called for
* An oxygen sensor is not reading (functioning) properly
* The engine coolant temperature sensor is not working properly
* Damaged or leaking exhaust manifold / catalytic converter / exhaust pipe
* Retarded spark timing
* The oxygen sensors in front and behind the converter are reporting too similar of readings