need some I sight from s2ki... I have the 05 ap2, all motor(I/H/E) with haltech 1000 tuned by Jeff Evans, noticed the car felt weird(slow), then watched my AFR gauge go crazy all over the place, bouncing between lean and rich, mostly running 15-afr or lower. Kinda scared the shit outta me, anyone have any idea what the cause might be? The car doesn't stutter or anything, and I really never heard a knocking car to be able to say if it did. Checked the plugs and they all look good(light brownish)....any ideas what's next? Check the primarily o2?

 

Does the Haltech run in closed loop? If so, the bouncing around stoich is normal. Did you just NOW realize that it was doing this?

 

Yes it does and it always bounces around so I've gotten used to it, I've had the wideband and EMS for 8months and about 3k mi now, so I have an idea what the norm is. this is different however, the readings would go in the 15s and even reach 17, which I have never seen with this tune. And then bounce back up to 13 but keeps returning to a super lean state, and then back again. Started the car today the idle seems fine at around 12.

Eventhough I've only had the wideband for a few months the Bosch sensor could be bad. Which sucks, to have it fail so soon but atleast it is a simple fix. This weekend I'm going to do a test on the sensor to see if it is infact bad, and will post.

I will say I have it mounted close to the secondary o2 sensor on the Js header which came with an extra bung made by Js so my guess the sensor mounting position is correct, so I hope I don't have to keep spending $100 every year on this part. I'll keep updating As I trouble shoot...

 

You could also have an exhaust leak but I'm sure you would have heard it.

 

Have you spoke to Jeff regarding your concern yet?

 

Yeah, he also told me to check out the AEM Wideband sensor test, most likely that's the issue. Will have some free time tomm to do it.

 

Ok, just finished the Wideband sensor test, and it came back negative, the sensor seems to be good. Drove the car around and didn't feel any stutter or bogging. The gauge still seems toact out of norm. Idle was good at 14.3, but as I moved through the gears at partial to full throttle I'd see 11-12s, and as I let off saw some 16s and 17s. Seem like normal numbers however never really seen it show that lean at injector cut off. At this point I'm feeling either I'm paranoid or don't know what I should do. Almost at the point of taking outthe EMS and putting onthe stock computer...

 

Next on the list will be making sure there are no exhaust leaks....

 

It's normal to see lean numbers when you let off the gas completely. The other side of things is on the rich side. Deffinently check for some exhaust leaks.

 

Yeah, just trying to figure out the best way, thanks man