Patt on early 1996 Rams they only had one upstream, later 1996 they had 2 upstream, so ONLY get a O2 marked UPSTREAM, no L or R marked one, otherwise it won't work. msheridan Sounds kinda like the problem I had... In my case it was bad main harness, bad PCM, and bad positive battery terminal...

 

That's what I figured so the o2 I recommended is an 'upstream' + it's a denso...so I guess it would be his 2nd one aka downstream that would need the non fouler on it..

 

I removed the valve covers to make sure all was in order and didn't notice any problems.

I also dropped the tank because the float was binding on the tank's wall. I replaced the ~8 inch piece of fuel line that connects the fuel pump to the hard line. The old one was a cheap piece of poly, and it was kinked to hell. My fuel pressure should be much better now.

New O2 sensor en-route.

I'm hoping I don't have to replace the PCM considering the money I've spent already. I'll start by checking for dirty grounds.

 

Well IF you should need a new PCM I know a guy I can get them from pretty inexpensively. But yeah hope it isn't the PCM...

 

Last night I removed the negative cable, and installed the new upstream O2 sensor. I drove it up the highway for a few miles and back down waiting for the CEL to illuminate, which it did. I passed my exit and went right to Autozone to grab the codes.

P0300, P0303, P0302 (Pending), and Bank 1 Sensor 2 High Voltage (The PCM finally recognizing that the cat is hollow). The CEL will flash at me whenever I hit 75MPH, religiously.

It does seem to run better with the new O2 sensor though.

If anyone has any more ideas before replacing my PCM, I'll give them a try.

 

Did you install the non fouler yet? Comp tests dry and wet, test the FI for those cylinders..EGR valve (could be stuck or going bad and camshaft position sensor. Is what I'd be doing/looking at and in that order. I doubt it's the PCM. It just needs to be tricked into think how you need it to.

 

P0300=Multiple cylinder misfire P0302=cylinder#2 misfire P0303=cylinder#3 misfire just an FYI in case you didn't already know..you could always put a cat back on her

 

Yank on the main engine harness while it is running. If it runs worse then better, your harness went bad.

 

Thanks for all the tips!

I'll be installing the non-foulers on the post-cat O2 sensor this weekend. I'll also give the harness a shake, and check its ground connections.

As far as I know, there is no EGR valve on my truck. The closest thing to it is the vapor canister purge solenoid.

 

Yup you should have an EGR valve if your sig is correct..if you didn't get the non fouler bring your o2 sensor with you so you can match the size I think it's a 18mm, not 100% tho..GL