a month ago i installed FMIC,UICP,LICP, turbo back, and MBC, the car had HKS intake installed on it before. so I had it custom tuned. the car went in limp mode once because it was over boosting. the MBC I had on wasnt really good so i changed it to Hallman MBC and set it to 21 psi. the car went into limp mode today again when it was at 21 psi in 5th gear and I have no idea why. what could have caused that? can someone please help

 

There is no reason to use a mbc in my opinion. If you have a good tune you shouldn't even need one. If I were you I'd go back to where you got it tuned and let them know that you're overboosting and tell them to fix it. All I can think of is you got a crappy tune. I've ran mine without a mbc up to 28 psi using an Access Port and never thrown a code or gone limp.

 

Airflow maps are not tuned correctly.

 

If you're running an aftermarket bov take it out and put the stock one back in, that will solve your problems.

 

why would be a bov the problem ?

 

It seems to be a common problem. I know that I had all kinds of issues with my car while I had an aftermarket bov installed; since I took it off I have not had a single problem.

 

basically these new breads of cars REQUIRE a retune when adding mods.

Any decent tuner should be able to fix limp mode

 

I didnt add any mods after my last custom tune...

and I know that bov could cause some problems.. but i cant see how it could be the reason for the car to go in limp mode

 

If you still have the stock metal BOV that won't cause you're overboost situation. My tuner tuned my stock MR to 22psi in 3rd gear and it's never went into limp mode for overboost. Take it back to your original tuner, if he can't fix it take it to a reputable tuner in this forum like Mellon or TTP.

 

oh sorry I didn't realise.

go back to your tuner and get them to either:
a) adjust the airflow + tq tables properly
b) see my DTC disable thread and use those codes for your car.

You can do b above if u have a tactrix OP20 cable

 

With all due respect, your DTC tables disable do not work.

 

For what DTC?

First ive heard of it??!?!

 

They worked great for me. My buddy was throwing codes and going into limp mode all the time. After using Tephras disable he has no more check engine lights and no more limp mode for 2 weeks now.

Why wouldn't you mention your findings in the disable thread?

 

Ok ... The car is not overboosting anymore and haven't been for the last month
it has been running great for that last month with no codes on until 2 days ago... it went into limp mode

So i got a friend to read the codes on the car after the car going into limp mode and there were 2 :
1-the airflow
2- car running lean

and the guy that tuned it is 350 miles away so its not really that easy for me to just go there and ask him to fix it, and even if i did so.. after what happened to the car, i don't trust him to do a good job fixing it.

Cobb is the only place that i can get my car tuned around here and i have to wait for 4-6 weeks to get it tuned there. plus they wont tune the car unless i get their AP which is $750 and a custom tune by them will also cost $700 which in my opinion is too expansive for a tune.

so should i wait for 4-6 weeks and pay $1450 for a tune or should i just drive 350 miles and get the guy that tuned my car to fix it?

 

They work 100%. Operator error or incorrect def if they aren't working.

I've tested it many times on many 10's, including one holding 30psi across to 8000 rpm.

it's actually really easy to test. Increase the airflow/torque maps until it triggers the CELS and limp mode. Then turn off the DTC's with tephras defs, keep the airflow/torque maps the same (that trip the limp mode) and run the car again, like magic, no more limp mode.

- Bryan