I think my CAT is plugged. Getting backfire under hard accel

[bluesyclone]

I think its my cat, but Im looking for opinons.
When I kickdown at about 40-50mph its hesitates, and usually backfires. the CAT stinks after it gets hot, so Im thinking shes junk. Any other thoughts? Also, Im running a stock turbo that was just rebulit. So, any suggestions on exhaust mods as long as Im spending money? Where I can get and stuff like that.
Thanks in advanace! Oh yeah, Im in WI, so emmissions is a non-issue!

 

[GM TURBO]

Ignition.

 

[Captain Morgan]

Ignition.

Vote #2 for ignition.

Cats are supposed to stink when they get hot, thats how you know they are working.

if ur cat was clogged, you would experience low if not zero boost.

change plugs, wires, cap, rotor and see what happens, even if is not, its still a good idea to tune it up, and its cheaper than a cat.

not sure if you have an AFPR, but low fuel pressure can cause those symptoms also.

 

[nick041881]

sounds to me like your getting bad detonation. when it backfires, does a puff of smoke and shit come out?

i would do what everybody else has said and go over your ignition. try running good gas and see if it goes away....my guess is that it will. btw: whats your fuel pressure set at???

nick

 

[bluesyclone]

How bad should that CAT stink?? It freakin wreaks!! I have cats on all my other cars, and they have never stunk like this sucker!
Also, not positive but it looks like a recent tune-up. I have no clue where the fuel pressure is set, I just got the truck last night. the truck has a few minor mods (ATR Stage 1 kit). So anythings possible as far as it being screwed with. Speaking of the Stage 1 kit, should I get a loud backlash type sound from the turbo when I let off after being underload? It that due to the cold-air kit? Ive owned another Ty, and a Sy before and never had that loud sound before. But they didnt have the coldair kits either.

 

[E-Rue]

ignition problem making you dump raw fuel into the cat. of course its gonna stink.

e

 

[Sy#26]

Clogged cat

Clogged cat

Had this problem on my Sy when I first got it. FP reg was stuck @ 80+psi, rich mix really gukked up the cat. Same symptoms. ONLY way to check is to saw the DP right before the cat & run it open - see if things improve. Easy to replace w/ pipe coupler & clamp(s). GMs method of measuring intake vacuum @ two different engine speeds does NOT work.

 

[bluesyclone]

Is there a good way to check the Fuel pressure at the rail possibly?

 

[GM TURBO]

Yes- with a fuel pressure gauge.

 

[THEMADTYPH00N]

should I get a loud backlash type sound from the turbo when I let off after being underload? It that due to the cold-air kit? Ive owned another Ty, and a Sy before and never had that loud sound before. But they didnt have the coldair kits either.

Yes it should make this noise. It's the compressor vanes fluttering.

Also Im surprised no one has said this earlier but you could probably figure out your problem fairly quickly with a good scan tool.

 

[bluesyclone]

Any suggestions on where, and what scan tool I should look for?

 

[Captain Morgan]

Also, not positive but it looks like a recent tune-up.

actually, it doesnt matter if the previous tuneup was done 30mins before you picked it up, unless you know the right parts were installed, it can still run like shit with new parts. It could have R43TS plugs, K-mart 7mm wires, and Tech 2000 cap and rotor. If you dont want to spend the $40-50 dollars on CR42TS plugs, Taylor Wires, and Conrad or Napa Gold cap and rotor, and have the piece of mind you KNOW the ignition is good, then knock urself out. Either way, I highly doubt the cat is causing backfire. Its either a fuel problem (too much or too little) or ignition, ignition is cheaper, any way you slice it.

 

[THEMADTYPH00N]

Datamaster, it's made by TTS Power Systems. It's a computer program so you'll need a laptop to run it .

You can get it at www.akmcables.com. They also sell the cable you'll need to hook the laptop to your car. HTH

 

[Tydriver]

ignition problem making you dump raw fuel into the cat. of course its gonna stink.

e

DITTO !

 

[BAD BOW TY]

I'll hook my datamaster up to it,if you want to drive around the lake to come visit,live in MI.

 

[myclone]

ignition problem making you dump raw fuel into the cat. of course its gonna stink.

e

DITTO !

You GO e... You'll make a hella mechanic one of these days. Fuel is what makes a cat con stink like rotten eggs.

Oh, BTW.. Could be a over rich prob due to malfunctioning MAP, vac hoses, FPR, etc. More possibilities than that but those are the easy ones to check.