o2 sensor problems! need help

[jnm2003]

I just put pacesetter LT headers and ORY on my truck. I dont have any cats and just my front o2 sensors. I got a tune from a shop in town and he turned off my 2 rear. I keep bringing it back to him because it keeps throwing codes. I have replace both o2s and checked for leaks. He cranks the truck and reads the o2 sensor readings while the computer is hooked to the truck. He says that its not reading what it should at lower rpms between idle to 1500. I know o2s only work during quarter throttle but why arent they correcting the problem? he has changed some settings and it still throws codes and doesnt know what else to do. i need help. Thx guys

[GasGuzzler]

If they won't read at low RPM there is either an exhaust leak ahead of the sensors (both sides and pretty bad?? NOT), the sensors are both bad (not likely), the sensors are too far from the engine (common problem with LT's, might wrap the headers to hold in heat), or the "tuner" has no idea what he is doing.

BTW, it might help to post the exact DTC numbers you have.

[skeet]

yep what GG said!! post the numbers and maybe we could give a little more input..

[jnm2003]

what are the dtc numbers? is that the codes that they are throwing? ill find out what they are. i need to talk to jeff that did the tune and see.

[jnm2003]

how does the heat mess with them? he said that he thought it might be the problem but maybe not to wrap the headers because it holds in moisture and will destroy the headers after a while. ill do it if i need to because im tired of the problem.

[GasGuzzler]

They need plenty of exhaust heat to work properly. Putting them too far from the engine in thin wall tubing can make them run too cool.

[jnm2003]

how can i wrap them to hold heat without destroying them bc it will hold in moisture? i dont have coated headers so i donno what to use. is there a certain type of sealer i can spray first before i wrap them so if the wrap holds moisture it wont hurt them? P.S. I wish now i would have bought the coated headers but this is what i get for having such a budget.

[jnm2003]

i got my codes. Its throwing code p0140 and p0160. we seen on the graph of the o2 sensor activity that at idle the line is straight (not pulsing) but somewhere between 1200 and 2000 rpms it starts reading a pulse like normal. I think it said for bank one and bank two it said insufficient activity. What do yall think? exhaust leak, or heat dissipation? or something else?

[GasGuzzler]

There's not enough HOT exhaust getting to them at lower RPM.

[jnm2003]

ok cool. well not cool but at least now i know. im gonna wrap them tomorrow then bc ive been waiting to see what to do and dying to fix it. thx GG