I just ordered an HKS high flow cat. I had the Cobb Cat on, and got a CEL after about 100 miles. What will I need so that it doesn't pop up again? Thanks...

 

O2 Spacer , $20 dollah & no more cel http://www.roadraceengineering.com/evox.htm

 

all you need is a product known as and antifoul for a sparkplug (18mm i believe). come two to a pack. they are like 5 bucks at advance and other parts stores. if you get a CEL drill the bottom out of one of the anti-foul adapters and your o2 sensor will screw right into it and then into the test pipe. if you get another CEL put another "spacer" (anti foul adapter) on but do not drill this one out. that is what i have done on 3 of my cars to get around the CEL from the cat. very cheap do it yourself fix.

 

ah okay, got it. i'm guessing i should just go ahead and get this instead of waiting for the CEL to come on in the first place

 

There was a vendor selling ones that have a 90 degree bend into them, those would probably work even better.

 

What is the code?

 

I have the "help" double anti-fouler pack i found at my local autozone installed on the cobb cat you sold me and i havent had a code yet in a few hundred miles,

 

+1 on the 90degree fouler. i tried the autozone idea and it didnt work.

 

With the help thing... you have to drill

 

ahh i see. well i'll try both ways if need be, what an annoyance that is

 

yeah i hate the CEL or anyother light that comes on, on the gauge cluster thing.

i have the UR resonated test pipe and it has never pulled a CEL

 

at one time, i had the CEL from the cat and the ASC light won't stop coming on, really annoying

 

These cars are so finicky.

With the EXACT same cat you have installed I havent had a single CEL and never had an ASC light. Im probably at over 330whp too.

 

I have exactly the same cat, same fix, same result (no more P0420).

I had done the same on my previous Evo 8 with WORKS high flow cat and it run for 3 years with no cel (and 3 Texas state inspections).

Highly recommended.

 

Good to know im not the only one.