Throwing Codes Daily

[35th-ANV-SS]

I have a 2002 Camaro SS with 14,700 miles on it. Within the past 3 weeks the SES light has triggered multiple times. I had the code pulled and then clear it. The code is P0174. After about 100 or so miles, the code triggers again. Today, the SES light came on again, and this time I had (2) P0300 codes, and (1) P0174 code.

My mods are SLP MAF, SLP smooth bellows, SLP lid, K&N air filter, Kook's 1-7/8 racing LTs, Kooks Y. I also have a lot of other mods, but they are not engine related.

The most recent mods were the headers and Y. When they installed the headers, I also had the cats removed and the air pump/system removed. Because of needing a speedometer correction from the 9"/gear install, they also removed the rear two O2 sensor codes.

After the first SES light which was the P0174 code, I changed the MAF back to the stock one and also put back on the OEM bellows. I changed this out yesterday. Today was when I got the P0300 code for the first time.

Again, the car has 14,500 miles on it and never threw a SES code until after my recent upgrades.

The car has not been tuned yet. Could all of this be from not having a tune?

Any suggestions?

[sunsetorangess]

Stay away from the SLP maf, your stocker will do fine well over 500 hp at the rear wheels.
I would say thats where the lean condition code came from could also explain the random misfire but i would check a few things.
Check your front 2 02 sensors and harness to ensure they arent melted to the headers.
Check your plug wires and make sure they arent melted to the headers.
I would also check the plugs to ensure that they werent cracked or chipped during the Lt instail.
Also check for leaks around the collectors and at the head.
And last but not least, it may be time to get a tune....
J

[35th-ANV-SS]

Thanks. I had the SLP MAF on for 2 years prior to getting the headers installed and never had a code thrown. Pretty much I have learned over the course of the last 6 months though that SLP is junk.

Also, I can smell what I thought was the car running rich. The inside of the exhaust tips are lined in black.

I'll check the things you mention below.

Is the car OK to drive like this? It seems to be running fine.

[35th-ANV-SS]

OK. Scratch the running fine part. It hesitates at around 2K-2300 RPM and also idle roughs. Idle is constant at 800 RPM, but the car shakes more than usual.

I looked at the plugs and wires and they all look fine to me. I'll be checking the O2 sensor wiring harness as soon as it cools down.

It didn't start running like this until I swapped back to the OEM MAF. Could be coincidental though.

[farmtruc]

The maf may have put the ltrims so high that when the other mods were added the pcm just reached it's limit of +25.

So, it could be a combination of things.

The 174 lean code is a vac leak, bad o2 sensors, bad maf signal, or all of the above.
The fuel you're smelling is due to the pcm detecting a lean condition. What happens is, the pcm detects a lean condition, tries to richen it up, but never satisfies the condition, so it keeps adding fuel to the point where it's too much.

If your car doesn't have a vac leak or bad o2's and it's just the maf causing this, it can be fixed in the calibration.

I've also seen headers cause the lean condition. Something about the placements of the o2s, the depth of the o2's in the collector or them not heating up good enough.
On some cars we've tried everything, relocating, sinking the o2 deeper in the air stream, etc. Replacing them with 02 corvette o2's fixed one vehicle.

later,
allen

[35th-ANV-SS]

It's odd you mention the PCM exceeding its limit. During the speedo calibration, I was told that the PCM was not communicating properly and they replaced it with a new one.

Tonight I am going to clean the OEM MAF and check the voltage reading on it. I am also going to try to check the O2 sensors/wiring harness. I won't get home until late, so we will see how it goes.

For reference, the SLP MAF was on before and after the header/new PCM install.

I just changed the MAF back to stock yesterday to try to see if it ran better. Which now, it is running even worse.

Thanks for the input!

[farmtruc]

It's odd you mention the PCM exceeding its limit. During the speedo calibration, I was told that the PCM was not communicating properly and they replaced it with a new one.

Tonight I am going to clean the OEM MAF and check the voltage reading on it. I am also going to try to check the O2 sensors/wiring harness. I won't get home until late, so we will see how it goes.

For reference, the SLP MAF was on before and after the header/new PCM install.

I just changed the MAF back to stock yesterday to try to see if it ran better. Which now, it is running even worse.

Thanks for the input!

The best way to check the o2's are with a scanner.
The o2's should be toggling up and down from 980mv to 50mv.
If they are not toggling up and down, and are stuck between 400mv and 600mv, they are usually bad.
Since they are reading and you're able to check them, they are probably hooked up correctly.
If they are not toggling, it could mean they are not positioned in the collector correctly, and the issue may be placement of the o2's, which i've seen before, it's a pita to fix them!

IF it's an air leak, the only sure way to find one is with a smoke machine. It pumps smoke through a vac line and where ever there's smoke, there is a leak.
We have one here and you'd be surprised that almost every vehicle has a vac leak, minor to major.

good luck,
allen

[allbaugh_04]

So what fixed the problem?

[35th-ANV-SS]

So what fixed the problem?

Tune

[allbaugh_04]

oh ok