Maggie Setup & P2135 - Help!

[Aaron407]

Avid maggie tuners running more than the out of the box kit but with a stock MAF, please read...

About a week ago I put LT headers and a 3.0" pulley on my TVS 1900 and saw an increase in my MAF readings (understandable). I noticed that it was getting very close to the 67.7 lb/min limit that a number of ECM tables have, with my readings being in the 65-66 lb/min area right before a WOT top end shift. I extrapolated my MAF table to account for the possibility of exceeding the stock 67.7 lb/min MAF plateau that starts at 11,850 Hz. Below are some of the other tables that have a max cell value of 67.7 lb/min:

In engine diagnostics:

Max Airflow vs. RPM
Max Airflow vs. IGNV
Airflow Delta

I previously posted a thread on g8board.com to inquire about those tables becoming a problem and causing a limp mode condition, but had no responses:
http://www.g8board.com/forums/showthread.php?t=152498 (hopefully the link is ok to include - mods, remove if necessary).

Yesterday, I changed a portion of the intake tract to replace the accordian coupler with a smooth silicone coupler, and noticed a bit of a seat of the pants increase in power. Today I was running WOT in 2nd gear and, right at the 2-3 shift, the car went into limp mode and cut power down to next to nothing. I was on a freeway, so I pulled over on the shoulder, reset the code, and was able to get it running again as if nothing had happened.

Stupidly, though, I neglected to write down the code since I was just wanting to safely get off the freeway, and figured resetting the code would kick it out of limp mode. However, I'm 95% sure it was P2135, which relates to throttle position sensor correlation. Since it never happened before this time, and happened right when I likely had airflows higher than below, I can't help but think that I exceeded the 67.7 lb/min limit that is in some of the tables and the ECM decided that the TPS reading must be faulty. A google search popped up a number of other people facing this same type of issue with a further modded maggie setup, but without any real resolution to the problem. I had assumed that the tables listed above wouldn't become an issue if the P0068 test RPM was set outside of normal operation limits.

So, my questions to figure this out:

1) Has anyone else faced this issue with any solutions?
2) For anyone running the stock MAF with MAF measurements that have exceeded 67.7 lb/min, would you be able to post your tune so I can see what DTCs you have turned off?
3) Does my logic above seem reasonable that it would be linked to exceeding a MAF table value somewhere?
4) Would anyone be willing to take a look at my attached tune and point out anything that could cause this problem? The only DTCs I have disabled are ones relating to catalytic converter inefficiency due to my HFCs, and one relating to the brake booster MAP that is typical for boosted applications.

Thanks for any insight! I'm scared to go WOT again until I get this figured out...

[Crazy8]

I used to randomly have the same issue and cel. On my car, it turned out to be a bad throttle body wiring extension. The one that comes with the Maggie to allow you to flip the throttle body upside down. I would have never figured it out on my own. My dad, who is an electronics professor, suggested it to me after looking at my car.

[Aaron407]

I'm leaning towards that as well. I surpassed the 67.7 lb/min level on a following scan without any issues, so I'm thinking it's not related to the table limits. However, the throttle body extension harness installation did not go nearly as planned when I installed my maggie and I ended up having to splice some wiring, so I've ordered a replacement extension that I'll install next week in hopes that it fixes the issue.

[Crazy8]

I'm leaning towards that as well. I surpassed the 67.7 lb/min level on a following scan without any issues, so I'm thinking it's not related to the table limits. However, the throttle body extension harness installation did not go nearly as planned when I installed my maggie and I ended up having to splice some wiring, so I've ordered a replacement extension that I'll install next week in hopes that it fixes the issue.

That is EXACTLY what my problem was. Spliced cables. It was enough to make the voltage fluctuate a little and trip the CEL.

[Aaron407]

That is EXACTLY what my problem was. Spliced cables. It was enough to make the voltage fluctuate a little and trip the CEL.

Good to know. Slowly but surely I'm getting everything sorted out with this car...