Baloo

9 year old stock exhaust system. Time to think about a change. Have a 11225 Magnaflow sitting around the shop so will use that.

My question is what have people been replacing there cats with and why? Not a Cali and would like to stick with Magnaflow however price is a concern.

Seems a waste to put that muffler on with stock cats.

mt_goat

You'll probably get a P0420 code with a single cat on the 2001 5VZFE. You can go with two cats or get a URD sim to get rid of the CEL.

Baloo

Damn, you're good. First it threw a code for the rear O2, which I replaced. Now I get the p0420 occasionally and crap mileage.

Do I just need the sim or do I need a test pipe (I think there is two cats)? How hard is it to "gut" the cats?

mt_goat

Not really, I was just speaking from experience, 2001 5VZFE (with a 2 cat ECU) and one cat used in the exhaust system. The P0420 is from insufficient cats, the URD sim just fakes the ECU into accepting the cat situation. The stock cats will flow fine unless they are clogged. I used a Magnaflow (Carsound) 2.5" diamater cat and 2.5" pipe all the way from the manifolds.

Baloo

Thanks. Ordering o2 sim today. Unfortunately have to drive this until it gets here, so hopefully mywallet is the only thing to get damaged.