Glowing exhaust

[Jeepfarmerjp]

Hi I am new to the site. I have red numerous discussions on the glowing exhaust but have not found my problem. I have replaced coolant sensor map sensor tps sensor idle control sensor new ntk o2 sensors along with new y pipewith mini cats and third main cat. I have unbolted muffler and it still glows. I have replaced spark plugs with the top of the line XP’s and mopar coil rail. I had it at the shop to have it hooked to computer they said all my fuel trims and stuff like that where spot on. Not throwing any codes. I don’t think it makes a difference but I replace the y pipe with flow master 2049170 it says it’s for an 04 but I don’t know any difference in exhaust. I have a 03 wrangler sport with the 42rle and 4.0 with 4” lift and on 33” tires. I have pressure tested motor and numbers are 165-180 and hold. I tested fuel rail and it holds at 49. Only thing I haven’t done is vacuum tested it but have sprayed starting fluid around potential areas with no jump in Rpms. I’m sorry for another glowing exhaust thread but all the others say it’s the cat or it’s a sensor or vacuum leak. And to help out it starts glowing first where the cats bolt to manifolds and works it way down but then the manifolds start glowing but I wonder if that is just because different materials. Motor is not overheating stays at 210 and fan kicks in out like normal. Any help would be greatly appreciated

 

[Indy]

How are your fuel injectors? Get them cleaned if they are too old.

 

[Jeepfarmerjp]

They are the stock injectors they have 114k miles on them. Would the mechanics computer not pick that up? I did test the injectors ohms and they were within specs. And for better information for y’all to help the second cat heats up just alittle before the first one.

 

[Fixer6]

Cats are plugged up

 

[Squatch]

it starts glowing first where the cats bolt to manifolds and works it way down

The cat would be where I'd look, if'n it was me. Back in the days when you could still buy leaded fuel, I witnessed a V8 Chevy Monza burn to the ground, starting with the red hot cats melting the carpet. She had been pumping (leaded) regular, trying to save a buck. Saw glowing red cats on an '80's Crown Victoria, too. Same issue...pumping leaded gas. Obviously, you're not doing that, as leaded gas is long gone, but still, sure sounds like a plugged cat to me.

 

[Jeepfarmerjp]

All three Cats are brand new replaced with ones I mentioned in first post. And have tested it with muffler off to make sure it wasn’t stoped up.

 

[Squatch]

All three Cats are brand new replaced with ones I mentioned in first post. And have tested it with muffler off to make sure it wasn’t stoped up.

My apologies. You did say that. Please disregard.

 

[Fixer6]

All three Cats are brand new replaced with ones I mentioned in first post. And have tested it with muffler off to make sure it wasn’t stoped up.

Sorry, I missed that as well. Almost always a restriction of some sort when any part of the exhaust starts glowing. That or you’re dumping raw fuel into and burning it in the exhaust. Might check to see if valves are leaking, or out of spec. If all the combustion is not being contained within the cylinder, and blowing by the valve, or timing is off could cause that too. The cats are designed to burn off residual fuel, but if you have more than residual going through, it’ll ignite that too.

 

[Paparock1]

the other side of the coin and what I have experienced in glowing exhaust manifolds were do to a lean condition. I only offer this to maybe help you troubleshoot.