Thread: '01 GT - No power, won't rev above 4k, hesitates badly.

Hey guys, really hope you can help me out here!

I have an '01 GT with 158k on the clock. Today while I was driving to work I suddenly had a huge loss of power, the engine wouldn't rev past 4000rpm, and I couldn't get past about 55mph. The engine was also hesitating very badly. If I put the pedal to the floor the motor makes a horrible knocking or detonation noise tryin to rev it quickly or above 4000rpm. Had a friend stick his hand behind the exhaust while I revved it and he said there wasn't much flow and the exhaust was really hot.

There strangely is no CEL....

Things I reckon may be wrong: clogged cat, clogged fuel filter, bad fuel pressure regulator, dieing ffuel pump, or bad MAF.

Anyone else have these symptoms and what the fix ended up being?

Thanks in advance for your help!!!!

I'm thinking clogged cat as well.

Thanks y'all.

Just one cat on the POS?

It works very well. That hole is enough for the exhaust to escape and allow the engine to breathe enough.

Thanks for your help. Cat was completely clogged, replaced and car drives almost like new again.

10 Gauge.......had the exact same thing happen here on my 00' GT.........mine backed up stream and burned out the air check valve when the heat built up. I replaced the crappy stock unit with an EBay Magnaflow direct fit......$164 shipped to my door. My car acted the same as yours....no power after only a minute of driving it up the road. It'd start fine and run decent for that time, but once the exhaust backed up.....crapola.
The car now runs like a raped ape and has a nice full tone to it. I had to replace the rear O2 sensor cause the old one was seized into the old cat, but all is good to go now.

I had the shop cut out the old one and just weld in a universal which looked to be bigger and less restrictive than the OE converter. They were able to salvage the o2 sensor. $210 installed and a new fuel filter and she hasn't run this good since 2001. Easily a 2-3x power increase.