I installed my Halltech Stinger-R a week ago and today I got these 3 codes this morning

P0171C-Fuel Trim System Lean Bank 1-B
P0174C-Fuel Trim System Lean Bank 2-B
B0516C- Speedometer Singnal Circuit Malfunction

I've seen other posts about the lean codes with the Z06 but I've got an '04 Coupe with 2000mi. Does this really have any effect on the car? Or is it just an annoyance to have to reset all the time?

Also whats the deal with the speed-O code??? Just a fluke?

I'm not too worried but just wondering.

Thanks!

 

I would think it would have relearned the A/F by now...the speedometer...no idea. Have you tried clearing the codes...disconnecting the battery for awhile and starting over with the relearn??

 

Weird. My 04 coupe has no issues with it. Go back and check again for leaks in the Air Bridge and coupler connections, and at the throttle body, anywhere behind the MAF meter. It sounds like you're getting more air introduced, after the MAF and therefore not accounted for when the computer adjusts the amount of fuel.

SpeedoCode? I bet fluke on that one.

 

Don't ignore this!
I swapped the air intake to the newer style on my '98 vert got some lean codes and well to make a long story short - I fried two pistons and a couple thousand dollars later it was all better
My guess would be air leaks - behind the MAF and not being monitored, but I'm a little twitchy about that
Good Luck!

 

As others said, make sure no leaks. I would pull the battery and reset the PCM. The PCM tables will update in about 50 miles. Your codes will be in history. If they come back as current, there is another problem.

 

I have peridoc lean codes w/ my Halltech. Not very often but they do happen. Jim told me that on 03, 04 cars they were subject to this issue over other years, but it's not a across the board statement for all o3's / 04's.

 

Thanks gang I cleared the codes and just drove her about 50 miles around Chicago up to Highland Park and back to Woodridge and no more codes. Checked for leaks and all seems good. Hopefully they won't come back and it was just a fluke!

As always this forum has the best members on the Web

 

That will not happen with lean codes, unless you have a major air leak somewhere.

This type of code happens as a result of the screenless MAF sensor, which is a poor air meter without the laminar screen.

At low rpm, the airflow going into the MAF is more turbulent due to the throttle plate being mostly shut, causing some air to be missed by the MAF and subsequently measured at the O2 sensors instead.

The difference between the measured air at the MAF and the actual Oxygen left over at the O2 sensor creates longer fuel trims to make up for the new measurement. This creates a long term trim in that particular fuel cell, which if 24% is reached (easy to do without a screen) the codes you mentioned pop.

You can reset the PCM, but better yet, pull the negative side of the battery all night to reset the LTFs.

This should solve the problem.

If they come back, you can install the 2001 Z06 MAF sensor, or reprogram your PCM for the LTF problem.

THIS CONDITION WILL NOT BURN PISTONS!

 

That will not happen with lean codes, unless you have a major air leak somewhere.

This type of code happens as a result of the screenless MAF sensor, which is a poor air meter without the laminar screen.

At low rpm, the airflow going into the MAF is more turbulent due to the throttle plate being mostly shut, causing some air to be missed by the MAF and subsequently measured at the O2 sensors instead.

The difference between the measured air at the MAF and the actual Oxygen left over at the O2 sensor creates longer fuel trims to make up for the new measurement. This creates a long term trim in that particular fuel cell, which if 24% is reached (easy to do without a screen) the codes you mentioned pop.

You can reset the PCM, but better yet, pull the negative side of the battery all night to reset the LTFs.

This should solve the problem.

If they come back, you can install the 2001 Z06 MAF sensor, or reprogram your PCM for the LTF problem.

THIS CONDITION WILL NOT BURN PISTONS!

Another option is to go back to the stock setup, but the former recommendations should be tried first.

This condition is never reported in the LS1, or 2001 Z06, since the MAF used has the proper laminar screen in place. Just like a wind tunnel laminar screen.

I understand that the 2005 LS2 will be going back to the laminar airflow screen as well.

Jim Hall

 

Had these! Major air leak! Mine happened to be at the PCV port (my Mag S/C had two...long stupid story...) but it was bad enough that the PCM couldn't adjust for it and the possibility of fried pistons was real.

Do Not Take This Lightly. Good luck finding it.

 

Welcome back, Jim. I hope all is well in Wisconson. Man, that's a tricky name for a city - reminds me of some of the names of cities in Connecticut!