2014 Problem!!!

[Malibuclc]

I have a 2014 silverado 1500 with the 4.3 v6. I decided to put a catback exhaust using a magnaflow 5x8 siso straight through muffler. I used 3" pipe and left out flapper valve. Had a local muffler shop do work. Muffler sounded horrible and performance was hurt, bogged down. 2 weeks later I had them put stock exhaust that I kept back on. Since then (about a month) performance has still been bogged down. Rpm's drop down and then gradually back up when stepping on gas. Very sluggish, sounds different. I have unplugged battery for at least 30 min. And even 24 hours multiple times and still no improvement. What is going on?

[SouthernSilveradoGuy85]

Even though 3" pipe in my opinion is too big for a V6, I think something was done when the shop put the exhaust on. I don't think an aftermarket exhaust with pipe that's only a little too big will make the truck bog down and still bog down with stock exhaust. Maybe a sensor was unplugged or something when they put the aftermarket exhaust on.

[seamus2154]

Yep, check the O2 sensors and any other wires that may have been touched, unplugged, or melted since that shop touched your truck.

[Malibuclc]

Thanks for the replies. I checked the sensors and they looked good. I think I found the problem though. The flapper valve never had problems but I clamped it open today and truck ran great. Maybe something in The valve deformed from the heat and wasn't working properly.

[SouthernSilveradoGuy85]

That still doesn't explain the problem with the aftermarket exhaust. I had everything from the muffler on back taken out and replaced with a single in/dual out muffler and 2 tailpipes. I don't have the flapper valve anymore and my truck has run fine before and after the exhaust. Exhaust was done July of '14 I think.

[ravageur1972]

probably his flapper valve tend to stay close......we don't know how exhaust was installed......maybe the mechanic heated too much and deformed valve and if it stay close it just increase backpressure as a blocked catalyser do

[SouthernSilveradoGuy85]

probably his flapper valve tend to stay close......we don't know how exhaust was installed......maybe the mechanic heated too much and deformed valve and if it stay close it just increase backpressure as a blocked catalyser do

 

He said when he had the exhaust done that he had them leave out the flapper valve.