z86trev

So I have had the car for almost two weeks and put about 70 miles on it. Last night the dang check engine light came on and gave me a p0420 code. It has SLP headers on it. Just wondering if the car should have 2 cats or one. And how many O2 sensors it has. I am pretty sure the scumbag that sold me the car and delivered it (30 miles or so) stopped and disconnected the battery on the way. Temp inspection is up tomorrow and it will not pass with the light on? Thanks

Injuneer

Your car has two catalytic converters, one for each bank (side) of the engine. There is an O2 sensor before each cat. That one controls the A/F ratio for that bank of the engine. There is an O2 sensor after each cat. That monitors the performance of the catalytic converter.

P0420 is telling you that the cat for the left bank (driver's side) of the engine is not working. Or possibly the after-cat O2 sensor is somehow faulty. Definite inspection rejection.

z86trev

Thanks for the help. I was pretty sure there were two cats and there was an o2 before aNd after each. I've been doing some searching on here And will swap rear o2s to see if code changes to po430 as has been suggested. I am pretty sure the guy I bought it from stopped on his way to my house to deliver it and disconnected the battery to clear the light. Wen I checked the code last night some of the monitors were not ready according to my scanner. My luck it's probably the cat.

z86trev

So i am going to have them programmed out for the time being and then "ahem" take care of them in the next few weeks.

GaryDoug

That should work as long as you don't mind the stink. It's more likely the cold weather that brought this on. My code 420 comes and goes with the seasons.

z86trev

My 06 TBSS had the same thing done by the previous owner. I can get used to the stink lol. Although being a convertible maybe I will just replace them.

z86trev

4 miles after clearing it, the p0420 is back throwing light

z86trev

Update : had a tune done last night. Car seems to run a lot better. There is a slight miss at idle, but the slight has stayed off. Inspection tomorrow morning.

GaryDoug

If NY checks the on-board test readiness indicators, they will see that some tests have not been run and will fail the inspection and tell you to come back later. Use your code reader to tell when the test results are all "ready". I am assuming you have a code reader and am not sure auto parts stores will give you that information using their readers. Try to drive a lot in various situations and speeds to get the on-board tests done before the inspection.

z86trev

30 miles into the tune and all but two of the monitors were ready. It would have passed like that, but I ended up doing about 90 miles with no issues and it passed with no problem. I turned the traction control off last night and gave it a good run. Car is very impressive. Work buddy was behind me and commented on how the *** kicked out back and forth but stayed between the lines lol

GaryDoug

It's going to cool off again for the next few days. See if the code comes back while you are driving in the blizzard ;-)

z86trev

It will be sleeping under a cover in about two hours. Lol