Hose 18 seems to be the one that is under there and runs to nowhere. However, I checked and everything else for the AIR is there.

Crappy photos again (I don't have a lift, ramps, etc. at the moment):

http://pafirefighter11.smugmug.com/p...GQsLGbr-XL.jpg

http://pafirefighter11.smugmug.com/p...T9S763F-XL.jpg

http://pafirefighter11.smugmug.com/p...xbHpBp9-XL.jpg



Never used a noid light. When my mechanic buddy listed to the injectors he said the #5 injector sounded different, but was making noise. I'm just going to pick up a used injector first to see if that does anything. If that's the case, great! If not, I'll get the noid kit.

Its just a little light that fits into the injector connector. The light blinks as power/ground is sent through it. If you are hearing noise though, I would assume it is alright but you know what they say. Also, I thought you said you swapped the injector around and the problem stayed, not followed the injector, which makes me think its not the entire issue. I have been wrong before!

Gotcha! We didn't swap the OE injectors around, we just used a Ford Injector we had laying around. Probably should've swapped the one injector to another cylinder, but it was freezing and we ran out of light. My buddy has a bunch of injectors from his f-body's laying around. I'm going to grab one and see if that does anything.

Oh ok, I thought you swapped it around and then swapped in the ford one. Must have been the coils I was thinking about.

That might just be part of the stock air intake resonator which looks like it was cut off. I can't remember for sure but I think the LS1 cars use the stock air filter box to filter air for the AIR setup. You might need to leave that open so the the AIR pump has an air source if that's what it is. Check your vacuum lines and double check the AIR check valves to make sure the air can only go one way.

It looks like #21 in your photo and that looks like it's just a vent hose.

No noid testing yet. Found more out today though...

#5 AND #7 injectors, when unplugged, have no bearing on how the car runs. 1, 2, 3, 4, 6, 8 all drop the idle immediately when unplugged, and it goes back up once plugged back in.

Replaced #5 injector with a confirmed working injector out of my buddies g/f's '98 Camaro SS that was wrecked. Same injector part #. Car ran great for about 1-2 minutes after startup, then went right back to ****.

My LS buddies (Two brothers who currently and have owned way too many f-body vehicles over the years) took a look at it. They mentioned wiring harness issues, but were perplexed. Said with the way it runs great sometimes at startup, but then other times doesn't, is very odd... Damn this car lol.

There might be an injector wire harness TSB on these cars so search around for that. Also look for a possible loose ground somewhere on the engine.

PCM shot, maybe?

Jeff, I'll check for the grounds next chance I get. I had to drive my TA in the snow today, driving like ****, 'cause I sold my Jeep and won't get my new one 'til Friday. FML. Is there a site to look up TSB's or would I need to call a dealer?

Bishop, I've been reading about people who think they have a bad PCM. It seems like I have some symptoms, but not all.

Odd thing I noticed yesterday is that my 3rd brake light is illuminated when I have my lights on, just like my rear running lights. It gets brighter when I hit my brake likes as would a rear running light. Also having the alarm issue where it goes off by itself after a car wash or in the rain - for no reason. My low coolant light is on but too, but haven't had time to check the level. Some other intermittent electrical things as well.

EDIT: My '01 PCM wouldn't work in my '98 right?

nope

Figured. Out of curiosity... I took the descreened MAF off my '01 and it's now on my '98. Would that be causing issues or are they the same 98-02?

A descreened MAF can cause a world of hurt. Speaking from firsthand experience. Try that and post up.

Okay, great. Will do that when I have free time, maybe tomorrow during lunch, and report back.

Speaking from tuning experience, don't descreen MAF sensors. Does far more harm than good.

I didn't - the ex did it lol. Then I bought her car as my project.

Odd thing - I disconnected the MAF last night, just for S&G's, then started it up. It ran like pure crap (worse than before). I plugged it back in and drove home. On the highway, in 5th gear, the car seemed to be running on 7, possibly even 7.5 cylinders lol, versus the 6 it was normally running on. Even on the back roads off the highway just before my house it ran better. The SES light wasn't even flashing as it used to do!

Then, this morning I started it up and it's back to 6 cylinders. SES flashes at speeds mainly above 35, as it did before.

I will be swapping MAF's back to my stock one today.

Check Engine light is still on? If so, what are the codes?

I reset the ECU by turning the key on, removing the two ECU fuses, turning the key off after 10 minutes, then replacing the fuses. SES light turned off. Car started up great. Drove for approx. 1 minute, then it went back to driving like ****.

SES light came on again after approx. 3 minutes, then blinking shortly after.

Codes listed on post #1:

P0420 - Original code I've had for over a year (Catalyst efficiency below threshold ...)
P0300 - Random misfire detected
P0140 - o2 circuit blah blah (from when I disconnected the driver side downstream o2 sensor)

Have not re-checked to see if there are any new codes.

ANY thoughts about just taking this to a Chevrolet Dealer/ or a High Performance shop with a good reputation? It seems like you'll make yourself crazy before you find the problem.

Maybe that cat is shot and making back pressure and the engine and messing with your o2

I think my next steps are:

-Driver side upstream o2
-Driver side cat

If it still sucks, I may consider taking it to Josh at JS Speed in Hulmeville, PA or to Andrew at CSP in West Chester, PA.

you should make a complete list of all the issues & alterations

P0420 is not an O2 sensor code. Lots of people think it is, but it has to be the MOST common code I see. Usually it's related to an exhaust leak, and judging by all that missing AIR stuff, I would venture a guess as to that being the problem?

P0140 code is more specific, but could still be the whole missing AIR stuff.

As for misfire, what else have you checked? Wires? Coils?

Al, I was thinking about this in one of the earlier pics. Looks like the AIR tube is open to atmospheric (not capped). I am unsure if you can run them like this.

Okay, went back and reread some of the stuff. You pulled the AIR stuff apart to get the plugs, so that makes sense as to why your are missing it in that picture. I hope that when you put it all back together that you used some sort of hi-temp gasket material so that you don't have leaks that could cause other problems on top of the problems you already have.

So you replaced the plugs and then all these problems came up, or did you have a problem then replace the plugs?
Have you checked the coil?
If he's misfiring like an "AK47", that will cause the O2 codes to trip. O2's are probably covered in a lot of fuel, and they looooove that.

Check the coils, might have a problem there. Swap some of them around, see if that changes the rate or the pitch of the misfires. You might be looking at one, or more, new coils.