Exhaust System Inspection

mrnickleye · 10-06-2005, 08:42 AM

scrufboy...I did the 2 1/2" exhaust with the Magnaflow muffler. I went ahead and put a Magnaflow 'OEM' cat conv. in too. (sometimes a 'highflow' cat will not pass emmisions in certain states). Anyway....It was WAY too loud (cops here in Calif have the total say over noise now). Plus it was a very annoying 'drone' sound at cruising at 2000rpm. So I added a 24' long resonator (4" diameter glass pack). No more drone sound, a bit quieter, but still loud, deep 6 cyl sound.

Also, you should be able to rev (and hold) the motor to redline easily. If not, then you may have a restriction in the exhaust system, usually the muffler or cat. And...the cat converter should NOT get red hot. That tells me there is a restiction, and the back pressure is so high that it is cooking the cat.

My 15 year old cat was still good, as it passed emissions right before I changed it.

Back in the 80's while 5 years at the dealer, I had to replace about 100 cats and mufflers (most under warranty) because they were a 'BB' filled type. They came apart and plugged the muffler. I saw many many 'red hot' exhausts. That's how I could quickly test it. The vehicle would usually not rev past 3000rpm, and the header pipe would start to glow red.

10-06-2005, 08:42 AM	#9
mrnickleye 1000whp postwhore Join Date: Jun 2005 Location: Mojave Desert, Calif. Posts: 1,705	scrufboy...I did the 2 1/2" exhaust with the Magnaflow muffler. I went ahead and put a Magnaflow 'OEM' cat conv. in too. (sometimes a 'highflow' cat will not pass emmisions in certain states). Anyway....It was WAY too loud (cops here in Calif have the total say over noise now). Plus it was a very annoying 'drone' sound at cruising at 2000rpm. So I added a 24' long resonator (4" diameter glass pack). No more drone sound, a bit quieter, but still loud, deep 6 cyl sound. Also, you should be able to rev (and hold) the motor to redline easily. If not, then you may have a restriction in the exhaust system, usually the muffler or cat. And...the cat converter should NOT get red hot. That tells me there is a restiction, and the back pressure is so high that it is cooking the cat. My 15 year old cat was still good, as it passed emissions right before I changed it. Back in the 80's while 5 years at the dealer, I had to replace about 100 cats and mufflers (most under warranty) because they were a 'BB' filled type. They came apart and plugged the muffler. I saw many many 'red hot' exhausts. That's how I could quickly test it. The vehicle would usually not rev past 3000rpm, and the header pipe would start to glow red.