My car is at Mazduh, and they can't seem to fix it. I just had a new motor put in, but now the car doesn't have the power it should. It accelerates ok at half throttle, but at full throttle it accelates slower. Or boggs down and hesitates, but only at full throttle. The only clue I have to what may be wrong is that the downpipe glows red. Any suggestions????

 

downpipe glows when there is exesive heat. When you run your car really hard for extended periods of time the turbos will create a ton of heat causing the dp to glow.

Your problem sounds like a fuel management issue.

 

thanks for the response ttpowered. I think there going to replace a fuel sensor underneath the intake. Does that sond right??

 

Check your main cat converter for clogging as well. Excess back-pressure will hold back heat dissipation.

 

How much mileage on the precat? Sounds like it's clogged.

 

do you have a downpipe or the stock pre cat...

a) precat is clogged
b) stock cat is clogged
c) fuel management issue

I thought you had a dp.....

 

It's the stock pre-cat and I have 52,000 miles on it.

 

Everyone thought you had an aftermarket downpipe....

 

I would replace the precat with a dp, then see where that leaves you. Then I would check into a hi flow cat, cat back, ecu, intake oops sorry, hehe
Seriously though I would look at that too.

 

sorry for the confussion. So a clogged precat could effect acceleration at full throttle?

 

Like the others said, either your pre-cat or main-cat is clogged (could be the reason for the blown engine) or you are running very lean for some reason (could also be the reason for the blown engine).

 

I had the fuel filter changed along with the new engine. So i don't think its fuel, not unless it's a sensor. Maybe I'll order a downpipe and try that. I never knew that a clogged pre-cat would cause me to accelerate faster at half throttle then full!

 

Don't really know about accelerating faster but the clogged precat will give more backpressure off the turbo probably allowing more torque down low. This clog will then give poor flow up top and aide in lower topend HP. Anyone can correct me if I am wrong.

I would just get a DP. If that doesn't happen to be the problem. Oh well. You still just gained HP, quicker spool, and enhanced sound.

 

You are correct Sir.