Hey Guys,

Just a question I have been seeing some KR in 4th gear at WOT about 4k(Cars pulling 4-6 Degs of timing). I thought I got some bad gas so I went and got about 3 gallons of CAM2 gas( 100 Sunoco Race gas) drove the car about 20-30 mins let it mix and did a couple 4th gear pulls and no light . About an hour later a got a P0420/P0430 cat below efficiency below threshold bank 1-2? I reset it, and this morning the car was back to puling timing in 4th WOT :/. thoughts, cat to exhaust gasket leak? Or do I have a sensor issue. I have had my exhaust set up for over a year and never seen a cat code.

 

Sounds like 02 sensor malfunctioning. Didn't you just have those replaced? Either that or your cats are bad maybe? Time for test pipes?

 

I don't think its the cats the Z1's are only a year old, only NA with them. The senors are the one's in the cats, I had on manifold sensor replaced and on cat sensor replaced in the last 6 months. :/

Test pipes NOPE Mass inspects for cats, and I can not shut the code off either :/ . What I might try is after I get my inspection is have Seb give me a tune with those off and just flip the tune with them on back in a month before I get my sticker,

 

I'm not a 100% sure a tune will solve the issue...I think when they run the test it goes out and looks for those sensors to be on..

 

It does, I wouldn't run that tune that has them "off" when I go to get my inspection. The odd thing to me is a have had the HFC's for over a year and never seen a light, I get headers, still no light yet, and we beat the crap out of the car on the dyno, LOL. I wash the car, spray the undercarriage to wash all the salt off the car from the last storm and and 1hr later the lights on? I have had to reset it now 3 times, Wonder if I got it wet and shorted it or at 86k miles and having them manifolds and cats on and off the car 3 times over the last few months I actually need one or two. I'm going to try changing them and see what happens, I also have extenders that came with the Z1 HFC's but when I called them they told me I didn't need them, and over a year went by before I had any CAT CEL's.

An I cant tell just by standing behind the car somethings a miss, I smell like fuel every time I go to the trunk to get something if the cars running LOL, like right NOW

My bigger issue is WHY is the car pulling 5-6 Deg's of timing above 4-5k

 

This is what's puzzling me as I read this. Consider when you throw a code, it's usually because the rear O2 sensor is too hot. It means that the cat isn't cooling the exhaust the way it should. If you are having excessively hot EGT (Exhaust Gas Temp), then it might be because you are leaning out temporarily. Do you have an EGT gauge? That would tell you if you're lean. If you are lean, it would det, and the knock sensors would trigger the timing being pulled. I would take a log under those conditions and sent it to Seb and see if he sees anything fishy there.

 

I have sent him logs we are working on it also, but is there a EGT log I havent poked around the ECUTEK software a ton yet.

 

I'm not familiar with what ECUtek has for this car, but out of the OBD, Dash Command can monitor the Catalyst Temperature bank 1 or 2. So I'm sure there's something in there that can log it.

 

Hm, thinking about this a little more - you may have a knock sensor on it's way out. If it's reading errant readings, then the ECU may be pulling timing because it *thinks* it's seeing knock. If it pulls 5-6 degrees of timing, that would RESULT in high EGT's. And the high EGT's could cause your O2 sensor to throw a code.

 

Or vise versa? I had two realy bad rear 02's. One was actaully telling the ECU is was lean and the car was super rich, car stunk, LOL I forgot to update here also of the readings. One reading was .29! Tech told me it is impossible to go over .28 :O, and that 02 was a flat lined DEAD LOL

 

Huh. Interesting that the car was changing timing off the REAR O2 sensor - I've never seen that before. So yup, there's your problem right there! Glad you got it sorted!

Out of curiosity, how many miles on those O2 sensors?

 

One is the stock 86k miles one was a aftermarket one about 1 year old , I don't think it was pulling from the rears but the feed the fronts and there's more than a 10% difference in banks also? Not sure about now, I sent a log to Seb after I reset the ECU yes it's still pulling timing also ;(

 

So car is still pig rich at idle, brand new 02 senor is still show "LEAN" and CEL light is back on after 40 miles same 4 codes!! P0420 and P0430. To be honest with everyone here if I can not get this ironed out this weekend when the car goes in to have the drivers side header replaced I'm putting all the stock stuff back on and moving on. I will have Z1's HFC's. Stillen Headers 1 brand new other 2 weeks old and Takeda cold air intakes for sale, only thing I don't have is the stock cat back so I cant sell the ARK . I am very frustrated right now I don't have time for this. Yea maybe I shouldn't mod :/.


I have a map update I need to log and log again, even that's a PIA

 

I hear you on the PIA. I've been so close to just walking away from a few cars in the past.

If the new sensors are still reading lean, then it's upstream or not related to the O2 sensors being faulty. If it's still pulling timing, it's related to either a sensor (my guess is knock sensor), or an injector not spraying in one cylinder, and detonating in that cylinder. I'd look at the sensor before I looked at the injector. But then again, if it's rich at idle, and lean while cruising, then it could be an injector that's clogged, limiting it's flow. Either way, it's pulling timing because it's getting a lean reading. So the two questions there are 1) is it 'actually' running lean, or 2) does it falsely 'think' it's running lean? If it's actually running lean, I'd point to an injector. If it just thinks it's running lean, then I'd look at the knock sensors.

Also, I don't think it's the tune. If you were running fine, and then all of a sudden this happened, it sounds like something broke. Unless the tune changed, then the hardware changed.

 

Thanx radio, yea nothing has changed , just one day after my dyno I stomped on not the light started blinking. And with in one day I started seeing these codes. All tho I honestly think it was the first time I got on it since then. One thing I know is the car was doing the exact thing when we started tuning. I was pulling crazy timing and Seb asked me about the roller setting in the dyno as he said the pulls where taking to long, so we adjusted the rollers down from 4000 to 2500( no clue what any of this means). If the kR sensor is bad wouldn't I see a different code?

Also for giggles I went back and flashed my old tune( before headers) just to test and it was still pulling timing but not as much and not as soon. I'm really hoping the cats are it cause if not I will walk away. As much as fun the car is I just can't be doing this with my DD. :/

I also think it's a "false" lean, Sebs tune the AF's are 12.5 or so oddly the other tune ( before headers) cars running 13.2's and pulling less timing ?