Bad H-Pipe?

[Black Sun 5.0]

I've had this ongoing overheating thing with my car. Stop and go or idle, everything is great. But hit the highway, and the temp climbs real well. Radiator, water pump, t-stat, etc. have all been ruled out. What about a bad h-pipe? I have one of those BBK pipes with cats. I know the cats are shot, I used to hear them rattling around down there and I no longer pass emissions. Any thoughts out there?

 

[green]

maybe the cats are plugged, alot of junk in them. that probally would do that. id take it out and beat the stuff out of them. just get a settl bar about 1 inch round and put the bar up there and beat all the stuff out.

 

[10HoleLX]

One easy way to check for clogged cats is like this.
With engine at operating temp (or close to it) try to feel if there is a major temperature change before and after the cats.
If its super hot before the cats and cooler after, then you have clogged cats.
Worth a try

 

[LT1Killa]

Uh... won't you burn the crap outta your hands doin that?

 

[88stangmangt]

Uh... won't you burn the crap outta your hands doin that?

um noooooo.................................. common sense will tell you to use a heat gun to test it out craftsman sells nice one's.

 

[5 Liter Mustang]

you dont literally have to hold your hand to the H-pipe.. if you are an inch or so off, you should be able to feel the temp. difference, w/o burning your hand.

I have one of those craftsman laser thermometors though... it does come in handy.

 

[ratrapp]

an easier way to tell is remove your two oxygen sensors and drive the car because this will give your exhaust gas a place to exit.it will be crappy sounding but it will tell you if thats the problem without gutting the converters.

 

[dvs bullet]

sometimes when yours cat are rattling the material inside can wedge itself sideways in the cat chamber causing a block in the pipe like the others said check the exhaust temp before and after. You should also hear a wheezing sound when you hit the gas

 

[Black Sun 5.0]

Wheezing sound, eh? We may be onto something here.