MasterWIII

First of all, I am a new member and glad I joined the YotaTech Team!
To cut to the chase, my CEL threw a PO420 code. So I'm getting a high flow cat. from LC Engineering. I also ordered some Doug Thorley Headers...for a single cat setup but I found out I have a dual cat. Sounds like a dumb question, but if I take out that front cat., am I going to throw another code for the front O2 sensor? Should I just keep it and send back the headers for a dual cat. setup, or is there another way around it? I'm hoping the high flow cat. fixes the PO420, if not I'll buy the simulator. Anyway, I appreciate any help or advice for this.

yotaman84

hang on your o2 is b4 the cats right?

MasterWIII

I'm not too sure where the sensor is located...I know that there should be two of them since I have a dual cat. Not sure if it's in front or behind though...seems like behind would make more sense.

mt_goat

One higtflow cat will not satisfy a dual cat ECU. I tried that and got a P0420 every other day (2001 ECU). I hear 2 highflow cats will work, something like this: https://www.yotatech.com/50673458-post26.html

But I"m just using the URD O2 simulator instead. Works great, no code since.

mt_goat

There needs to be a front pre-cat sensor and a post-cat sensor, even if you use the URD simulator.

The front sensor is VERY year specific because it helps control the air/fuel ratio. The newer trucks like 2001 (maybe sooner) and up use a wideband O2 sensor. Only use OEM sensors if replacing one, URD sells them. http://www.urdusa.com/product_info.p...s_id=430006000

The sensors should also be put in the system as close to the factory locations as possible, especially the front sensor. Not sure how anyone does that with headers unless they only use one exhaust stream (bank).

I'd highly recommend using flex couplings after each header collector to keep the headers from cracking later.

Personally I'd skip the headers and get a supercharger if you have the need for speed hehe.