If you are already going into that area, it may be a great thing to consider doing while you got it apart.

Eric, what signal are you using for the front 02 sensors with your cats removed?

I saw a piece today on Extreme 4 by 4 where he showed the difference between a "normal" 02 sensor showiing either rich or lean and the newer "Wide Band" 02 sensors that have precise signals and an advanced ecu that is now available for precise tuning. It was interresting, but I only caught th last portion of it.

Sorry I meant to reply to you earlier about this Danny. I kept the O2 sensors hooked up as stock. The CATs sit in between the front and rear sensors, so I just cut them out and left the O2 bungs intact on the Y-pipe.

Eric, going back to my previous post on the misfires, since I had a similar problem with my '98 (AEL) I keep the truck as well tuned up as possible yet was still getting a random misfire code as well as the misfire causing excessive emissions codes ( and I have a new y-pipe & cats & o2's !!!) ......however , occasionally I would get a P1447--evap purge valve poor performance code,......which led me to investigate the AEL system , I determined that the purge valve was working....maybe working too good...It was on the instant I turned on the key, and never shut until I turned off the key....INSTANT & permanent vac leak !! I installed a cheap rubber vac cap on the port on the throttle body where the purge line should go...left everything else alone. 3 tanks of gas & 3 weeks later ....knock on wood...no misfire codes...and the idle seems smoother. I havent had the time yet to figure out exactly what's going on with the purge system..making the valve stay on always....but I'm happy for now just to get the damn CEL to stay off. I realize that this may not be your specific problem but a $.50 rubber cap may be the answer for now, or at least help you to narrow it down ....good luck

Actually I capped it off yesterday and removed all the AEL guts. Codes popped back up immediately, but I cleared it again and it hasn't come back. Got to drive some more to see.

how far back did you "gut " , all the way to the tank or just the canister ? I left mine in tact so as not to set off any other codes if I could help it, I even left the valve & solenoid plugged in.....(we have some really picky state inspection guys here )

No inspections here so all I left was the tube to the tank. I really should remove that and cap it off too. With the ultragauge I can just ignore any AEL or CAT related codes.

The front O2's work if the cats are there or not.
The front O2's monitor/control engine fueling.
The rear O2's only tell the ECU if the cats are working or not, they have ZERO effect on fuel mixture.

The evap solenoids are known to get stuck open and throw a code. The vent hose for the fuel filler are also known to dry rot, causing a roundabout vac leak with the solenoid wide open. The vent hose was a biotch to change on my '97, the end is between the edge of the tank and the fuel pump access cover.

The rear sensors are there to tell the emissions man if you have been bad or good. They will most likely not throw a code if the ECU can read a signal from them.

I just did not realize if he cut it out prior to or after the 02's guys. I though maybe he had somehow omitted them. Sorry if I was confusing.

How important are the clips? I ordered the Bosch injectors and mine don't have the clip - can I just safety wire these in place?