1999 GTS - Exhaust Manifolds Glowing Red

[emjohn43]

I know, I know...Vipers are hot. But this seems very very hot.

The car: 1999 GT-S, 9500 miles. No cats, rear muffler delete. Recently cleaned (RC Fuel Injection) injectors; after cleaning, all came back with a good bill of health. 100% OEM tune on the PCM.

If I start the car, let it idle for 5 minutes (or longer), the headers are already glowing red. I would understand if they were glowing after the car was just run through the gears, but literally not touching the gas on a cold-start idle for 5 minutes....seems off to me.

O2 sensors? Intake manifold gasket? Or just straight....normal?

 

[GTS Dean]

O2s are first check for proper function. Also check OBD tables for extreme adaptive trim settings. Maybe your mufflers are plugging up. Also keep in mind that the later Gen 2's came with thin-wall tubular steel headers instead of cast iron and it may not be uncommon for them to glow at idle. I just don't have experience with them.

 

[99RT10GTS]

It sounds like cats!!! Or as Dean said, mufflers. Go straight pipe or your injectors are ******. I have a set just cleaned and check for sale

 

[efnfast]

If you don't have cats/mufflers it's most likely unburnt fuel in the exhaust, either too rich or timing is too r-e-t-a-r-d-e-d. Checks O2s are working and what the fuel trims are as a starting point.

 

[TEALLIFE]

Id figure out why the fuel mixture is that far off at idle asap before running it anymore.. O2s, stuck injector...

Check the temps on each of the runners coming off the head to see if one isnt firing and dumping fuel.