i got the car a week ago, stock everything, checked for codes, data, everything shows good, even closed loop, but there is no reading from the tps, MAF readings are in the 36000 range, changed both sensors with new ones, still pops backfires when past 2000rpms, has new plugs,wires,correct timing at 6' with est unhooked, car is nice but its driving me nuts! all everything is plugged in except emission junk, getting a code for tps, maf voltage and est, wth?!?!

 

oh yeah, running hogrich and sounds like its got a nice cam, til you reset the ecm, and it idles between 1200/1500

 

You may have a bad ecm. Check your car for bad grounds first. There should be a major ground point behind your passenger side head with one of the wires looking like a shoe lace.

 

You will continue to get code 42(EST) unless you unhook your neg. battery cable for a few minutes to reset the ecm.

 

changed computers already, checks all body, chassis,engine grounds, injectors all ohm at 17

 

Unplug the Maf and start it up. See if it runs better.

 

If you have a new tps with the same problem, then I would try running new wires from the ecm to the tps. http://www.chevytalk.org/fusionbb/sh...hp?tid/241136/ Check out that wiring diagram.

 

maf unplugged makes no difference, im checkin out those schematics now thanks nintyone

 

You said the original MAF was reading 36,000, and you replaced it. What readings are you getting with the new MAF. They should read 3,000 at idle and about 9,000 at 3000 rpm under no load.