I have a 2005 cavalier-2.2 eco 5 speed-so far i've made a custom ram air intake(honda civic pipe cut to bout 10-12 inches long, w/the 90 degree elbow, i have a 2.25 exhaust pipe from basically the down pipe, to and from my 2.25 inlet/outlet hi flow magnaflow cat, to my 2.25 borla muffler-my car blew up my stock cat which is why i put the magnaflow on there-since i've put the hi flow on my car has been sending the code P0420-anyone know what keeps sending this or how i can get rid of it? my mechanic thinks i need more power at idle to keep the cat working.....im not sure tho-thanks in advance


"I can't believe you are doin all this to a Cavalier!"-Everybody Else
"Hey-at least its not a damn civic!!"-ME

P0420 = Catalyst System Efficiency Below Threshold

Which basically means you need a new cat. But since you have a new high flow on there. It means the cat is not removing enough gases from the exhaust.

I got this after putting on a 2.5" exhuast and high flow cat.

I went to the auto parts store, and bought "Help 18mm anti- foulers" . Yes it's for spark plugs, but it works, and it's a $5 fix.

There are 2 in a pack. Take a 7/16" or 1/2" drill bit and hollow the little hole out of one. This is so the O2 sensor can fit in it. Unscrcrew the O2 sensor after the cat. Then screw the non- drilled one in to the hole on the pipe. Then screw in the drilled one in to the undrilled one. Then screw in the O2 sensor. Make sure you get your codes cleared after this. I did this about 2 months ago and I still have not had the code come back.

That or get a $40-$60 O2 simulator, if they even make one for your car.

its the high flow cat.

just get o2 simulators.

OK....

Lets buy a $40-60 electric part that most likely won't work, or if it does, not for very long. Instead of doing 5 minutes worth of work and spending 5 dollars.

That's intelligent!

Just to add, this fix is still on my car and working perfectly for about 8 months now and counting. But yea go spend that extra $$$ for a crap electric part that most likely won't work.

Xian G wrote:OK....

Lets buy a $40-60 electric part that most likely won't work, or if it does, not for very long. Instead of doing 5 minutes worth of work and spending 5 dollars.

That's intelligent!

Just to add, this fix is still on my car and working perfectly for about 8 months now and counting. But yea go spend that extra $$$ for a crap electric part that most likely won't work.

its $20 and does work. its been proven by several. theres no swear item so it works forever. your solution is homebrew and hasnt been proven.

Hasn't been proven?

I think having it on my car for almost a year now and 8 months in a different exhaust once before is proof enough. And it is still working with the same set of things from either exhuast.

Not to mention the 5 other JBO members here in FL that I know to be using them is proof enough.

your highflow is marginally failing the efficiency threshold. your band-aid of a solution just bumps it above that threshold.

could you send me the R+D findings, plz? along with some snapshot files and passed ready status? what about long term durability? could you post upt he 5 year test results for us.


kthxbye.

If I was Cody, I would try the $5 fix. If it doesn't work, I could go to the more expensive O2 simulator.

Also I believe there are no sims available for the eco. If I am wrong please let me know I contacted casper personally and they said they did not have them. That was a few months ago.

theyre universal.

and for me time is money, so 2 minutes to splice 4 wires is better than toying around with drilling and tapping and guessing at something that will have to be redone when the inspection catches it.

^^^^^ He's trying to help someone out and if 5-10 people have it done and no problems that that is r&d. That is more r&d that rksport has and will ever do for an o2 sim. I would say try the defoulers because there is enough reason out there that they work and if for some reason it dosen't then your only out 5 bucks instead of spending 15 for something you didn't need. Oh yea that overpaid e check worker (who are usually in there teens and twenties) are not going to know what it is or think it's a problem. They probally think it came that way. But they'll notice taped up wire way before the bung being out further.

I hate hack jobs but there is nothing that seems to be hack about this. I would just chill out.



Quote: no ofence man but if you have so much experience in all that why does your car look like crap?