Pulling the Cats

[swathdiver]

Has anyone done this to a GMT900 in their driveway?

The service manual calls for removing the transmission cross member. I saw a guy on youtube leave that alone and remove the sway bar bolts so it could be moved around but I think that was an GMT800 truck.

I wonder if there's enough clearance to remove and replace them using jackstands?

 

[iamdub]

Would cutting the crossover pipe help much? You could get a coupler to put it back together. If it were me, I'd do what I could to get it out conventionally, but 10 seconds with a sawz-all and a $10 coupler might be worth saving all the hassle. It looks like most aftermarket Y-pipes are 2- or even 3-piece designs and they have a coupler on that part.

 

[swathdiver]

I think your right and that it would. Cleared the code and it came back the next day. Filled with 93 octane, it was on E85, cleared the code and it did not come back. Drove sixty miles or so on the highway and the numbers look perfect, a little off at idle compared to Bank 1 but not enough to set a code.

Have read that E85 has a cleansing effect on the fuel system, maybe it dislodged some "dirt" which got caught in the cat and had to burn off. Sounds good anyways.

Alcohol content went from 58% to 14% and will fill up in a few days and check the numbers after that then.

Having said that, it looks like changing the cats is not needed now. Without that Tech2, I would have spent $1200+

 

[sumo]

I have. You need plenty of clearance to maneuver the pipes around. I was replacing my headers so i ended up sawall below the cats so they would drop out. On my American racing headers, the manifolds were one piece then the catted y section.

 

[sumo]

Make that 4 separate pieces

 

[swathdiver]

What does a set up like that run? What kind of performance and where in the RPM band does it give?

 

[sumo]

What does a set up like that run? What kind of performance and where in the RPM band does it give?

Around 1500. I’ve gained more than 50hp. I have a supercharger so better flow me

 

[swathdiver]

Thanks!

 

[Rocket Man]

I love my AR headers on my '02. When I had to replace my trans they made it so easy to pull the midpipes with the cats and then the trans. Cat replacement will be super easy too when the time comes, just pull the mids and work on the cats off the truck.

 

[swathdiver]

The P0430 came back today. 99% of the time I remote start the truck and get underway with the engine at or nearly at operating temperature. Not so today, I got in and started driving and before long the code set.

Cleared the code, fuel trims and the specs for each bank of the engine is either even or within 1% of the other side. That right cat is a little off the left at times but otherwise seems ok.

Side note, with the key on and engine off and the tech2 on, I turned the key off and then on and started the truck. All of the dash warning lights came and the tech2 froze and lost comms with the Candi. I lost count of all the codes but was able to reset all but 9, they just won't go away. All of them had to do with losing communication. All 9 codes in the radio module remain but the radio and back up camera and seemingly everything else works just fine still.