ok i had a problem last week where i picked up a miss and my exhaust manifolds where glowing. It was the plug wires on the back two cylinders where not on all the way because of the metal heat sheilds. so i inspected the wires and put them back on and now it runs fine but in normal driving down the express way at 75 for 10 miles or so the manifolds still start glowing by the back four cylinders. Now i only have 300miles on the car sence i put a motor with 63k miles on it and i have not noticed this before and i drove around for a night with the hood of when i first finished the car so im sure i would of noticed that night. any ideas on where to go next. Also with having put a diffrent motor in that i believe has a cam would i have to have the car electronically tuned or dino tuned

 

headers or actual stock manifolds? at least at night you'll see header primaries glow, but it also can be an indication of running lean. best thing is to scan the pcm and see what's happening.

 

It could be possible that you fouled the plugs as well, did you check the condition of those? Also, if your car has a different motor with a different cam, depending on the specs of the cam, it may very well need some tuning.

 

Please put your mods/car/year in sig so we can help you better

 

Check for vacuum leaks or throttle body elbow leaks (any air that is getting in downstream of the MAF).

 

these are stock manifolds i really have no mods that i know of the car is a 96 i bought it blown up and bought a motor off ebay and they didn't say there were any mods but it really acts like it has a cam in it. thanks for the ideas and any more will help

 

Okay, how was the car running so that you think it has a cam? Does it choke when your floor it? If you have a clogged CAT the stock manifolds will glow and the car will run like complete crap (i had that happen).

 

X2 on the clogged cat. that would be the first thing i would check. un hook the cat and then run the motor and see if they glow.

 

not so easy on a stock car where the cat is welded to the Y

Signs of a bad cat:
Glowing Manifolds
Glowing Cat
metallic clunkity sounds when idling coming from the Cat
Total Loss of power at higher RPMs,
Loss of power in general
Chunks of honeycomb flyign out your exhaust

 

I agree, check the cat's, I had that happen to me before too. whether they are bolted on or not, they are probably clogged.