Is it possible that the cat. on my 98 1500 can be clogged at one of the inlets and not the other? The short side inlet is way hotter than the driver side inlet. The outlet is cooler so I assume its bad anyway. The plenum gasket was blown and replaced last year. And the cat. checked out fine then. Can the blown plenum ruin the cat. over time before it was fixed? I'm asking these questions because the truck never had any power. And the cat was replaced about 2 years before the plenum gasket was replaced. Of course I am not the original owner so I don't know how long the plenum gasket was bad. TIA john

 

The driver's side inlet has a longer tube to come from that side of the truck so would have a little more time and surface area to cool. A bad plenum gasket could ruin a cat if it was bad enough and left long enough.

 

Thanks! It was bad . And the #6 and #8 sparkplugs were wasted. I just don't know how long it went on for. Anyway, I tested for a plenum leak yesterday and all is well.

Magnaflow cat on the way for friday delivery.

 

You'll like that magnaflow. I just put one on my truck and have been impressed.

If you ordered the direct fit from Summit it's no more than a 1.5 hour job including the "victory" beer.

Good luck.

 

For those of you whohave installed a magnaflow cat, did you notice that your truck sounds a lot louder afterward? I installed a mangnaflow highflow cat and it sounds like I have no cat at all. Anyone else notice this?

 

I just hope I gain some power. The thing has been a dog since day 1. It only has 3.55's but jeese.

 

Yes,the high flow cat will make the truck a little louder because of the increased exhaust flow.

But,more sound,means more flow,means more POWER!

Enjoy.

 

Mine actually got a lot quieter when I put the cat on...then again I was running it with nothing but pipe coming off the exhaust manifolds

I don't think this is off topic. At what point do I need to make other modifications to the intake, fuel delivery, coils and the like to compensate for all of the unrestricted exhaust flow? My truck is louder, but feels less powerful than it did when I bought it stock. It almost feels like a hollow spot similar to a dirty carb on a motorcycle, very little power and labored between 2-4k rpms.

I searched but can't find anything definitive on this. Is it possible to over do it? What is the most logical "next step" if you think you may have over exhausted?

Thanks in advance for your help... I hope I'm not "exhausting" anyone with my questions! (that was soo bad I'm almost proud of it)

 

Although I have a pressure tester for the exhaust I decided again today, after I got home to check the cat. temps again. While it was idling I got a reading of about 380 F on the short side at the weld to cat. On the passenger side inlet at the inlet weld to the cat. I got 340. The outlet at the weld is only 240! Not goog I'd say.

 

Ok! Now I'm getting pissed and confused! LOL Did a vaccum check and it is completely normal. So I got under it again after revving it up doing the vac check and the temp at the outlet of cat is like almost 100 degrees hotter than the inlets .WTH ?