98 Pcm And Rear O2 Question ?????

[madbrian]

i have had major problems with sorting out bad running under 3,000 revs in my 1999 gts.

i previously fitted a brand new 1998 pcm.
can anyone tell me if this is still working my rear 02 sensors and if so i read a previous post stating that the rear o2 sensors can cause misfiring etc.

any comments ,thanks.

 

[uvbnbit]

I think the rear O2's only tell the PCM if the cats are working properly. I don't think affect anything else.

 

[madbrian]

i found this and it started me thinking
RTTTTed

Western Canada VCA Member





Join Date: Jun 2007
Location: Nimpo Lake, BC
Posts: 4,667



Re: car running TERRIBLE..no power..gas smell on start-up
Could be rear oxy sensors. My car changes tune depending on rear 02 sensors or Simms. Changing between the two was only way to get car running good (after hundreds of miles). I know, that's not possible - but it's what is happening.

Any CEL?

Send me PM if/when finding the problem.

Ted
__________________
Roe Supercharged 01 Sapphire GTS, M2 built 720rwhp. rest-mod 440 Duster 4sale, '92 IROC R/T 4sale, 71 340 Demon project 4sale.

 

[Madduc]

Have you called Chuck Tator yet? I would STRONGLY suggest you do. In another thread of yours you seem to have an unknown front o2 sensor and one factory o2 sensor. Get new ones from Dodge(Tator). Have him explain to you how to do a "Field Dump". re-check your throttle body sync. I'd also get a fresh set of plugs in it at the same time.

Also...call Chuck!!! 914 763-3136

 

[madbrian]

is a Field Dump when you clear the pcm by grounding the positive connector at the battery rather than removing the 3 plugs at the pcm ?

 

[CWhiteRun]

Do you have a different exhaust? If so, an inexpensive fix that has worked for me on vehicles in the past is to get a spark plug anti-fowler and install them on the rear O2 sensors and then put them back in the exhaust. The anti-fowler limits what the sensor can "sniff" and may get rid of the CEL if it is on. Engine grounds, MAP sensor, plug wires, fuel pressure, and EGR are some of the most common items to cause misfires in other vehicles...not too sure if the viper would be any different.