o2 simulator help

[bonnip2000]

i have a 2000gtp, just put a new engine in it and new Orings, to find out that the check engine light is still on, bank one sensor 2( back o2 sensor im told) but i have discovered that i dont have a back o2 sensor but a cat. then simulator then cherry pipe? It was my understanding that the simulator should mimic the back o2 sensor and not set off the ses light? i guess my question is, should i replace the front o2 sensor since im running rich on the fuel(the inspector said that not me)? or do i need to replace the whole exhaust system back to original code? any help and thoughts would be appreciated.

[BNaylor]

Welcome to AF.

Are you the original owner or did you install the 02 simulator? It should preclude any post CAT converter (bank 1, sensor 2) 02 sensor DTCs like P0420. Thats how mine work. Maybe its defective.

Did the inspector provide any ST/LT fuel trim values to see how rich or how far out of spec. If the front 02 sensor is really flaky you should get a P0171 or P0172 DTC.

[bonnip2000]

no i did not install it, i bought the car two years ago at a auction and replaced the engine due to a bad valve, now i need it inspected and the service engine light is on. the inspector didnt give me any values because it couldnt run the test on all computer components since it hadnt been driven but 20 miles after the computer was reset. but now the light is back on and when he was inspecting it he said he could smell gas from the exhaust and suspected the light would come back on again once i drove it alittle more.. he was right :-(

[BNaylor]

Do you have access to an odb-ii scanner? Autozone nearby? You might double check and see what a second opinion says and if any other relevant DTCs are showing. A rear 02 sensor DTC should not affect the fuel injection system or short term/long term lean/rich fuel trim. Only there to monitor CAT converter efficiency.

[bonnip2000]

yes i can go and recheck it out i know the code did say bank one sensor 2 , but i had a fuel leak ( bad Orings), had that repaired yesterday.. could that be the cause of the problem?

[BNaylor]

Leaking fuel injector o-rings or fuel supply line o-rings can cause issues and trip the SES/CEL light. And cause the lean fuel trim which causes more fuel to the fuel injection system. Good thing you got that 'cause the primary concern would be an engine fire.

[bonnip2000]

thanks for all your help, i appreciate it very much. I took it to a muffler shop today and they said they need to replace the cat, and cut out the cherry bomb, and put a back o2 sensor back on it.. so im out another 450$ :-( but hopefully that fixes the issue and i can get my baby back on the road! Hope you have a happy holiday and again thanks for all the help!