new Carven TR muffler/Performance Issues

[Em Vee]

Hello Chevy fam,

I am new to the forums. I wanted to see if someone on here could help me out.
I recently got the Carven TR 3" muffler installed on my 2003 Tahoe z71. Before the muffler I had 0 issues. Now, I noticed the vehicle is very slouchy and doesnt up and go like before prior to the muffler install. It is especially noticable when going up big hills. Before the vehicle would shift down and make it up the hill. Now it shifts down and still drops speed drastically.
Nothing major is done to the vehicle. I have a superchips Dashpaq with the "tow tune", 17" pro comp 97 series (steel) wheels with 285/70/17 pro comp AT tires and brand new NGK iridium spark plugs with ACDelco wires.
Anyone have any idea what is going on?
Thank you in advance.

 

[S33k3r]

When did you add the tires?

 

[Doubeleive]

doubtful a muffler caused any problem, you might want to check your maf & fuel pressure

 

[Em Vee]

When did you add the tires?

The tires have been on the car since I bought it which was over a year ago.

 

[Em Vee]

doubtful a muffler caused any problem, you might want to check your maf & fuel pressure

wouldnt both of those things cause a check engine light though? I dont have a check engine light at all.

 

[Doubeleive]

wouldnt both of those things cause a check engine light though? I dont have a check engine light at all.

the maf could throw a code-yes, the fuel pressure no
the maf can also be giving bad readings and still not throw a code

 

[Joseph Garcia]

Time to get a Tech 2 or equivalent hooked up to the truck for some diagnostics.

 

[Sam Harris]

Who did the muffler installation..? I’d guess something was damaged during this. Perhaps a wire was nicked / burned. Fuel pressure definitely needs to be checked. Could even have a smashed fuel line or something like that, adjacent to the muffler install.

 

[Em Vee]

the maf could throw a code-yes, the fuel pressure no
the maf can also be giving bad readings and still not throw a code

Okay awesome. I will look into both. Thanks brother.

 

[Em Vee]

Who did the muffler installation..? I’d guess something was damaged during this. Perhaps a wire was nicked / burned. Fuel pressure definitely needs to be checked. Could even have a smashed fuel line or something like that, adjacent to the muffler install.

I’ll have that checked out, thank you.

 

[HD_LS]

Did they do any welding, when they installed the muffler? Welding can cause stray currents & voltages that can damage one of the modules.

 

[Em Vee]

Did they do any welding, when they installed the muffler? Welding can cause stray currents & voltages that can damage one of the modules.

Yes they welded the muffler on. I will check under there and see if they might have burnt any wires or anything.
I am also thinking the steel wheels are making it slouchy too. They are 42 pounds each according to Pro Comp. Thats HEAVY.

 

[Sam Harris]

Yes they welded the muffler on. I will check under there and see if they might have burnt any wires or anything.
I am also thinking the steel wheels are making it slouchy too. They are 42 pounds each according to Pro Comp. Thats HEAVY.

True, but your issue sounds bigger than heavy wheels.

Re-reading your post, you also installed new wires and plugs at the same time? Or were you just listing what had been done since you purchased it?

If those were done at the same time, I’d definitely be looking into the plugs and wires, making sure they’re as they should be. I had ARH longtubes installed at a very reputable shop, and at the same time, he did ARP bolts in the headers and plugs and wires since he was there. But dude is an exhaust guy, not a mechanic.. I had 3 or 4 plugs actually loose in the holes. Wires were installed ok though. Heh.

 

[Em Vee]

Well the car was running bad since I got the muffler installed. I got the plugs and wires done the next day because I thought maybe the plugs and wires were old, but it still drove the same even after.

 

[Em Vee]

True, but your issue sounds bigger than heavy wheels.

Re-reading your post, you also installed new wires and plugs at the same time? Or were you just listing what had been done since you purchased it?

If those were done at the same time, I’d definitely be looking into the plugs and wires, making sure they’re as they should be. I had ARH longtubes installed at a very reputable shop, and at the same time, he did ARP bolts in the headers and plugs and wires since he was there. But dude is an exhaust guy, not a mechanic.. I had 3 or 4 plugs actually loose in the holes. Wires were installed ok though. Heh.

Well the car was running bad since I got the muffler installed. I got the plugs and wires done the next day because I thought maybe the plugs and wires were old, but it still drove the same even after.

 

[Em Vee]

Hey guys, thank you all for your input. I found the problem. Clogged Catalytic converter. Problem is now fixed.

 

[Sam Harris]

Hey guys, thank you all for your input. I found the problem. Clogged Catalytic converter. Problem is now fixed.

Glad to hear it was identified. Interesting that this wasn’t identified until after the muffler install..

 

[Em Vee]

according to the muffler shop it became more noticable with the new muffler because of the change in flow. Going from a really big 22" muffler to a small 14" muffler caused a change in flow especially in the low rpm range. Now that the catalytic converter was changed it feels like a new car again. Im just happy that it drives better.