How Many of You all Have removed your Cats?

LeeS · May 13, 2002

:baa: Hey Guys!

I have a 2002 Silverado 5.3 Engine. I have removed the Catalyst Converters. I didn't see any Bluish smoke before I removed the Converters. Now when I let my truck Idle for 2 or 3 Mins and hit the gas I see Bluish smoke that comes out of the dual Exhaust I have. I stinks sortive like fuel but I am worried that it might be oil smoke. HAS ANY OF YOU SEEN THIS?

Keep In Mind that I have no Cats or my Truck. It only happens after it idles 2 or 3 Mins.

I am using O2 Simulators from Caspers Electronics to fool the Computer into thinking I have cats on!!!!!!

It doesn't smoke any in the morning after it has set overnight so I just wonder if this could be fuel flood smoke. It is Bluish in color.

Stomper · May 13, 2002

Not sure about your smoke problem but I was wondering what kind of exhaust setup you have. What mufflers are you running if any? Can you tell its a lot loader with out the cats? I'm running a 40 Series Flow Master with cats and its not very load at all.

LeeS · May 13, 2002

It is a whole lot louder without the cats. It sounds great and has a rumble to it. I think you would like the sound.

I just wished I knew someone who had taken their cats off if they seen the same unburnt fuel or if mine is using oil.

My truck only has 5,124 miles on it.

MarkD · May 13, 2002

Occasionally new mufflers, especially flowmasters have a "burn-in" period. I think some type of coating in/on the muffler will burn off. This may or may not be causing the smoke. I have witnessed a change in tone after 1000 miles or so on several vehicles (especially w/Flowmaster).

What mufflers do you have, or have you changed them?

Did you unplug your PCM/battery for 30 min + when you changed the exhaust?

gmcjoe · May 13, 2002

Still have the cats here. These days these things flow much better and I haven't done any mods to justify removing them yet.

Z71GUY · May 13, 2002

With todays engines, I would leave the cat's on. Like another member suggested, it just might be burning in. I bought a new exhaust system for my 400EX (quad) and it smoked for awhile until the packing material was broken in. The gas you smell will probably be a normal smell since you have used the O2 simulators....they are probably giving a slightly lean signal which will make the truck run a tad richer. I have seen kits that will relocated your O2 sensors....I'd recommend this route rather than using the simulators. To get your max performance, you will want your computer getting real world data.