stock cat and ABS sensor

[Z Ya Later]

Hey, anyone know what the stock size of the cat is? I'm looking to replace it and wonder if a 3" will fit well with the stock exhaust as well as the loudmouth coming down the road. Also, anyone know what the GM part # is for the right front ABS sensor? Thanks.

[Joe 1320]

Just a heads up on the ABS sensor..... you can't replace just the sensor, you have to replace the entire hub /bearing assembly. It is a sealed unit.

[Injuneer]

The outlet of the cat goes into a 2-3/4" intermediate pipe. Most cat-back replacements increase that IM ipe to 3". The Y-pipe appears to be similar on the inlet end of the Cat, but I never measured it. I would think that you wouldn't want to use anything less than a 3" high flow cat. But many of them come with "plain" ends, and need to be adapted to fit any particular system. The stock system has a weld on the front of the cat, so the old one needs to be cut off. Then you need to either weld in the front of the cat, or have flanges added. In the back, as I recall (I haven't had the stock exhaust for at least 4 years) there is a GM specific "ball flange" used on the cat.

There are 4th Gen specific replacements available, that will have the required outlet flange.

[Z Ya Later]

Thanks for the help guys. I'm going to have my exhaust shop do the cat, but I needed to know if I could get away with a 3" on the stock exhaust system as well as the loudmouth. As I was informed earlier, I know that the ABS sensor is part of the hub assembly, but do you know the part #? Thanks a bunch guys.

[Joe 1320]

1993-2002 front wheel hub #7470587 $136.28

[Z Ya Later]

Sweet, thanks man. You still got that assembly from your car? Interested in selling it? lol BTW, update on my GN...the cam sprocket on the timing chaing stripped and bent 3 valves...hurts just thinkning about it

[Joe 1320]

Originally posted by Steve93Z
Sweet, thanks man. You still got that assembly from your car? Interested in selling it? lol BTW, update on my GN...the cam sprocket on the timing chaing stripped and bent 3 valves...hurts just thinkning about it

Ouch..... did that once too. The stocker is a POS. I do still have two assemblies. Let me know if ya want one or both... they will be cheap.

[Z Ya Later]

Yeah, we are to happy about it either. But, she comes home tomorrow with the new timing chaing set, reworked heads and the crack welded up on the stock POS dirver's header. Lemme know how much you want for both...might as well do both while I'm doing the brakes. Won't be for another few weeks though, as I'm going to upgrade the rotors and pads at the same time. Also, are there any actual benefits to having the LT4 knock module vs. the stock one? Thanks again man.

[Joe 1320]

The headers will most likely crack again unless additional bracing is added. A triangle shaped brace welded from the "log" to the runner will help. Sooner or later they all crack. I ended up getting a set of ceramic coated Poston's headers. 4 years later they still look brand new.



The LT4 knock module will help filter out drivetrain noises, will give you less knock retard in the upper rpms and especially on a gearshift. My car used to feel a little flat during and immediatly after a gearshift and sure enough, the scanner was showing a couple degrees of knock retard. After the addition of the LT4 module, the car pulled harder though the gear change, the flat spot was gone. A highly recommended mod for the dough.

The hubs are kinda heavy, so e-mail me your info so I can see how much the shipping will be and I'll get back with ya.