holeshot69

So the car failed emissions, went in with two 02 codes so I wasn't really expecting anything. So I swapped the primary and reset the ecu, tada! No codes for almost a week. Chuck it back in for etesting throws a code during higher rpm section of testing and fails. Not a big deal conditional pass and I'm off for my sticker.



What I've done as for moding: I/H/E and 1.8 conversion for ecu and cam. Oils, plugs, wires are all best I can get along with proper maintenance.



Next step is hopefully leaning out some, so I have grabbed an Apexi SAFC and the wideband will be ordered this week. Question is will this be enough to get me away from running rich?



Right now the 02's are positioned in the header at the top of the runner ( towards the block ) and at the end of the down pipe. That meaning they are both before the cat, I have a sneeky suspicion our cars do not like this. But with tuning it will balance itself out? I have a spark plug non fouler ready to go in if that is a good idea at the moment.



Does the secondary 02 sensor control fuel more significantly then the primary? At that point the non fouler or swap? Swap does suck as my parts dealer won't return if it's used.



Tell me what to try here guys. I don't care for the code as they say it running rich, but power loss does suck. On that note not a really noticeable difference in fuel mileage.

TibbyTurbo

I suggest to move your cat before the second o2 I used to keep getting CEL but after moving the cat its all good now just recently pass my emission

tanc

Primary before the cat 2econdary after. How close is that primary to the head? Any exhaust leaks



Reset the ecu, drive like a gramma and the fuel trims will lean themselves.

i8acobra

2nd O2 sensor MUST go after the cat. It doesn't have anything to do with fueling. It's only purpose is to test if the cat is working or not. The ECU compares the readings from the 2 O2 sensors to determine if the cat is working. The second O2 sensor should have a "cleaner" reading that the first sensor.

holeshot69

Okay my mechanic suggested having the secondary were it is wouldn't hurt, but I will go with this advice as I thought this aswell.



No exhaust leaks and the primary is very nearly at the collector of the 4-1.



Okay so at this point I will have to plug the current location and extend the wiring for the secondary. I seem to remember there being issues with extending wiring. What should I do there? Should I just grab a standard plug for the current hole for the 02?



Thanks very much guys, I do appreciate the help.

ChattTownShark

^^ what he said that should fix all of your problems make sure to reset the ecu and drive granny for 30-50 miles then youll be all good

holeshot69

Here's the update on this. We swapped the 02's around to different places, the secondary after the cat and the primary to the place were the secondary used to be. So the primary is now in the single pipe after the collector.



We cleared the codes and took it for a drive, no lights on.Then they were nice enough to do a mock test for o2. I passed quite a bit more then the first time! However my HC's and nitric oxide level are both high. So they say that the HC's will probably look after themselves but the nitric oxide level is a problem.



The suggestion was made I could dump in a stage cooler plug to help a bit. But the level is caused by the rich condition. Hence why when I started the car after class right then a code came up. Haven't checked it yet, but the car is running better no doubt.



Well what do you think about this everyone? Next step?

i8acobra

Could also have a bad cat, or one that's the wrong size, if it's aftermarket.

holeshot69

Hmmm it has taken a beating. I have a magnaflow high flow on it. It matches the rest of the tubing as far as sizing.



Any significance with getting a code at start up as apposed to while driving? Previous times were during high rpm driving.

Plugs perhaps?



Totally lost here, and I can definitely smell some unburnt fuel around the olde cannon.