[Shadows Stall]

I have a 2000 Mustang GT I just purchased with 79k on it. The car had a bad catalytic converter on the driver side it and was knocking and glowing red. I replaced both of them instead of one just to do it the right way cat. After we finished I started the car and drove it like 2 miles if that and looked under neath to see the the catalytic converter was glowing red on the driver side again but it wasn't making the knocking noise inside this time! The check engine light is on and the code is P0174 (Fuel trim bank 2 condition) I am unsure of what is wrong. The car has no power and runs very rough. What can cause this to glow like this? Please help it am losing my mind. Can it be caused from a bad coil? Please help. What can all of the posibilitys be? It feels like its missing but could that cause the cat on the driver side to glow red?! Thanks Mike.

[stlwagon]

You are running lean but it sounds like it's dumping raw gas into the cats. Get it looked at immediately.

[Mustang50LX]

my guess would be possibly an O2 sensor

[silver 4.6]

im good with exhaust issues, but ive not come across something like this.

ive got a good guess.

your engine is running with tooooooo much fuel, cats burn excess fuel in the exhaust, and if theres to much, they will do their job for extended amounts of time and start to glow.

try replacing spark plugs or wires, maybe one cylinder isnt firing, giving you that miss.

as i said, im good with exhaust, so i cant tell you how to fix it, i only know the problem.

good luck

[Crazystang89]

The cat is clogged. Is you're car pretty high mileage? You'll need new cats and your tune could be contributing to it. (Too much fuel)

[Shadows Stall]

i just put new cats on it today and the only one glowing is on the drive side. I am thinking possibly coil packs maybe or something around those line. any more info would be great. Also as far as I know the car has a stock tune nothing done.

[00BLACKSTANG]

Code P0174 usually pops out because a lot of mustang owners like to install the cold air intake and some install a bigger air mass meter and thats when it gets worse. If this happened because you did some thing to the intake part is running lean to much air or not enough gas or sensors are bad. Since you already replace the cats is not it is not the COPS (no miss fire code?)I think is more like a sensor

[JC316]

Leaning out is what causes the cats to heat up. I would recommend changing out the O2 sensors and see if it helps.

On a side note, what kind of knocking was it making? Only at idle? I have a mystery knock that has persisted after an engine rebuild and a new motor. Wondering if it's coming from the inside of the cat.

[Crazystang89]

I'm sorry. I was being stupid and didn't read where you had just replaced the cats. Definitely in the tune.