NastyNate65

I just put my LTs on and had my y pipe welded to the catback. Instead of buying O2 extensions I moved some pins around in the PCM to make the computer think the rear O2s are the front O2s so that I could just plug the rears into the slots on the headers. I saw a thread about it a while back, ill try to find it again. Anyways my question is, i dont have my codes deleted yet, so is that one of the reasons why it is not idling smoothly? Or are the rear O2s physically different than the front ones? Any experience/advice is welcome.

Justus67

iTrader: (3)

Re-arrenging pins and playing with the pcm has never came out good for me. I used the O2 simulators for the rear with mine and the longer vette O2 sensors for the fronts. No problems and no codes.

Pitbull329

iTrader: (3)

Might be a leak somewhere? When I did the pcm pin swap, I still used the rear o2s.

It idled fine. Didn't have codes deleted and I had also done EGR and AIR delete. I drove it around for sometime, and it drove fine.

NastyNate65

I also deleted AIR and EGR and made block off plates for the headers. I will try to plug in the front O2s in the rear spot and into the headers and see if it makes a difference. Also there is a leak where the drivers side header meets the y pipe. Im going to take it back to the shop on monday and have them weld it shut. But will a leak really make that much of a difference on the quality of idle?

NastyNate65

How much did the vette O2s run you? If i cant figure this out im gonna swap the pins back and use the vette O2s.

Pitbull329

iTrader: (3)

Depends how bad the leak is? (not to sure if it'd affect it bad)

What I did, was get copper ultra silicone and put a bead around the band clamps on the the header collectors. Worked great

NastyNate65

Here are the links to the pin swap

https://ls1tech.com/forums/pcm-diagn...front-o2s.html

http://www.ls2.com/boggs/torques/98pinpcm.htm

Has anybody had success with this?

Soul Crusher

Are they the same pins on the 99-02 cars? I heard there were some differences in the 98 PCM. True?

Pitbull329

iTrader: (3)

Nope, not the same! I havent checked the 00-02 pins. The 99 pins are different from the 98.

Soul Crusher

Well if anyone knows the 99-02 pins (I have a 00 T/A) I'd thank you to post up the info. I'm about to install a set of headers.

NastyNate65

All i know is the 98s are different from the 99-02s. But apparently the 99s are different from the 00-02s also. I have not had success so far with my pin swap, but i am going to pull the PCM off again and check to make sure they are all in the right spot. If they are all correct, i might just swap them back and buy some rear vette O2s and see if the car runs better with those.