2001 pontiac grand prix catalytic converter

**Reeddawgy** · 06-01-2008

Hey, guys whats up..... Ok I'm trying to remove my catalytic converter from my exhaust system (2001 grand prix). The problem is that I'm not sure which one it is. Coming down from the engine it turns about 45 degrees and goes into a box then out, then straight with a sensor screwed into the pipe, then into another round muffler looking thing with a heat shield tacked onto it. Eventually finishing with the 2 mufflers ending at the tail pipes. Which of those front 2 is the Cat

? Thanks guys in advance

**BlitzGT** · 06-01-2008

Umm. Yea...

Its right in front of the Ubend.

Remove the Ubend first, its more restrictive than the cat.

**Reeddawgy** · 06-01-2008

Originally Posted by BlitzGT

Umm. Yea...

Its right in front of the Ubend.

Remove the Ubend first, its more restrictive than the cat.

Thanks blitz! Ok let me get this right..... Now i see a pipe coming down from the engine with about a 45 degree bend in it. Is this the u-bend you're referring to? If so, do you mean behind/aft of it? It seems to be one whole cast piece. It bolts to the bottom of the engine which i assume is the exhaust manifold and then bolts after the built in box after the sensor.

**Sabrewings** · 06-01-2008

The u-bend he's referring to is where the sensor is mounted (see how its shaped like a U?).

The catalytic converter is right before the u-bend. The resonator is the other item you see further back (near the back seats).

Maybe this will help you:

http://www.naioa.com/v2/modules.php?...wtopic&t=13427

**Reeddawgy** · 06-01-2008

Originally Posted by Sabrewings

The u-bend he's referring to is where the sensor is mounted (see how its shaped like a U?).

The catalytic converter is right before the u-bend. The resonator is the other item you see further back (near the back seats).

Maybe this will help you:

http://www.naioa.com/v2/modules.php?...wtopic&t=13427

Thanks Sabrewings

, that helped alot. So i can just cut that out and straight pipe it to the resonator i'm assuming right

?! Then what do i do with the sensor afterwards

? Thanks again guys. You're a wealth of information. Love this site!!

**Sabrewings** · 06-01-2008

Originally Posted by Reeddawgy

Then what do i do with the sensor afterwards

?

Most people just turn it to the 3 o'clock position and weld a bung for it. Or you could leave it out entirely and get the code removed from your PCM.

**Reeddawgy** · 06-01-2008

Originally Posted by Sabrewings

Most people just turn it to the 3 o'clock position and weld a bung for it. Or you could leave it out entirely and get the code removed from your PCM.

I'm new at this obviously. So i'm guessing that you mean turn it upwards to a 3 O'clock position and screw it into a threaded something that I weld or clamp to a area nearby?! Bung? Like bung hole

?!

Thanks man i"m almost there now.

**Sabrewings** · 06-01-2008

Originally Posted by Reeddawgy

I'm new at this obviously. So i'm guessing that you mean turn it upwards to a 3 O'clock position and screw it into a threaded something that I weld or clamp to a area nearby?!

3 o'clock would be 90* to the side. So, straight out towards the right side of the car.

Originally Posted by Reeddawgy

Bung? Like bung hole

?!

Thanks man i"m almost there now.

The bung is the circular part that's welded onto the hole in the pipe for the sensor to thread in to. Here's a pic:

**03GPScottyd** · 06-02-2008

You could check out a 2.5" or 3" DP that includes a free flowing or deleted CAT with a bung already welded in that is a direct bolt up to your existing system from wbodystore or zzperformance etc...

Stock U-bend

Downpipe with no u-bend - $184 doesn't include tax.

U-bend delete welded into your existing exhaust - $54 doesn't include tax.