I installed the 2 non foulers and it worked for about 30mi but my cel came back on. Any suggestions if this code is something other than my o2 catching the cat being "bad" or should I try three foulers? Any help would be appreciated. I have the rrm headers with the cat.

 

Are you sure the only code you are throwing is p0420? If so then that code is strictly for the rear o2 sensor. Back in the day when I used the anti-fouler method I only needed one and it worked perfectly. Now I have the code cleared from my ecu so I dont have any installed.

 

Yeah I had the P0177 too but I put new spark plugs cleaned my maf changed oil and my air filter. It got rid of that one. But the reason I was doing all this because I had to emissions test and I failed but I passed when I finished that work. Where could I get it removed?

 

Yeah the only code I'm throwing is the p0420 code. I got it checked today again. I tried one fouler i have one on there now.