PO420 Code
#1
PO420 Code
I just installed a high flow downpipe on my 2004 Monte Carlo SS and now im getting a PO420. I was thinking of using an O2 emulator to trick the pcm in thinking the cat is good but to my understanding they wont work on 2004+ vehicles. Is the only way to get rid of this code by sending it in and having the code deleted out of my pcm or is there a better option?
#2
P0420 is cat efficiency. If you deleted the cat then that's why its on, or if you put a high flow cat in it, then the pcm may not be liking it. It has to detect a differance in the front and rear o2 sensor readings. If the cat isn't doing a good enough job and the readings are too similar between the 2 02 sensors, it will throw the code. The only way to delete the code is to use a scan tool (autozone may even do it no charge). I've never used an 02 emulator so I don't know if it will keep the light off or not
#3
The that they have in AutoZone will only erase your code. Not completely remove it from you r PCM. I know that there are a few members here that have the O2 Emulator and they say it works perfectly.
Check back later on to see if any of them post. Its a holiday weekend so they might not be here as often as they usually are.
Check back later on to see if any of them post. Its a holiday weekend so they might not be here as often as they usually are.
#4
I just got a ZZP 2.5 downpipe with high flow cat installed 2 days ago. My rear O2 senor was bad so yesterday I had them install a new one (they had to order it). So far so good without throwing any codes. I drove the car approx 10 highway miles. Do you think you might have a bad O2 sensor? My car has 62500 miles on it so I'm not sure when they go bad, if it's by age or mileage.
#5
I thought he just wanted the light out, lol, I didn't know u could completely remove a code
#6
The code will come back.
Amy, it may not show with that few of miles. It's my understanding it takes three start cycles (tests) before it trips the CEL.
#8
The O2 sensor is working perfectly. I know its because of the cat because i got the light after i installed the downpipe. Remember mine is a 2004 so take a look at this link... http://www.3800performance.com/Merch...oduct_Count=17
#9
Non fouler
Has anybody tried the non fouler mod? It's supposed to create more distance between the O2 sensor and the exhaust gas that's either been through a high flow cat or none at all. The resulting difference should supposedly take out the codes.
Non Fouler Link
Non Fouler Link
#10
The O2 sensor is working perfectly. I know its because of the cat because i got the light after i installed the downpipe. Remember mine is a 2004 so take a look at this link... http://www.3800performance.com/Merch...oduct_Count=17
Well, I thought my O2 sensor was OK before too, but after they took it off the car it looked all burnt and stuff, so I got a new one installed. It's been a week and still no code has been thrown.