It is getting cold around here. My gauge has been warning me much more often and in earlier gears, so I knew my boost was higher due to temps.

I decided to log while picking up dinner, in order to see what my zt-2 was reading.

Did a couple of pulls in 2nd and 3rd. Then on the way home. one in 4th only to 5.5K. Then shortly later in 5th it happens.

I start hitting boost hard and hear a pop, with total loss of power. I have nothing and hardly get of the road. My car is chugging hard, bouncing hard and quick between .5K and 1.5K. I could barely move in first.

I shut it off in turning lane and refired. Nothing changed. Pulled off to a safe spot, shut off, pop hood in dark, check for popped off something.

I get back in and start the car. Everything is good. I drive the last minute home and carefully boost to like 10 psi once with no problem.

I have a check engine light now and will go to Auto zone in the morning.
My AFR was 11.9 to 12.1 on the 4th gear pull, but was 12.6 to 12.8 when the pop happened. My car ran very lean suddenly. Also my rpm's on the log are screwed up on the last pull and never read higher than 3,100 rpm. but boost reached 24.3 psi in 4th and 25.3 psi in 5th when it popped..

Any help would be appreciated very much.

I am hoping it is just a MAF, but it felt really bad. What does blown engine feel like?

 

Sounds like something popped off or you threw a p1241 code.

 

P1235 is my bet. It causes a crazy limp mode like what you've experienced.

You DO NOT need an MBC. Flat out that's your problem. Too much boost with it in the cold.

You might check your relay, since that's awfully lean on pump gas (assuming that's WOT, at partial throttle it's fine).

 

I actually went into limp mode earlier that day, for the first time since tune this summer. This was much more noticable then limp mode. I could not even really move.

Poor evo was hyperventilating. I'm scared.

 

I was hoping to get a 3-port soon, since I dont like the temp variance.

Yes it was WOT on all pulls. I switched the relay once with fog light one at 5k. 8k now. Will it be visibly blown?

 

So my codes are: P0222 TPS (Sub) Low, P1234 TPS (Sub) plausibility, P1235 MAP/AFS plausibility

Antilock brake menu: U1417 Implausible coding data, C121C Torque Request Signal Denied

I have since turned my mbc down one rotation.

Car seems fine. So I believe it was, as statd by goofygrin the harsh limp mode P1235??? Because I hit 25psi boost???
Is that to protect the engine?

Either way I am still concerned about the AFR. I didn't know that temps can change AFR like that, since it was tuned in 100*F???

Input on these codes please

 

those are all airflow related. It's not that 25 is too high, but it's out of the tuned parameters.

You need to take the MBC out and get retuned with the stock ECU boost control. You don't need a three port. Just do it. The ECU will manage the boost better and will not cause these issues. I was tuned in 90* weather and it was 35 today and my car was loving it

 

I will get a 3-port soon (GM, Grimmspeed, Perrin) I will retune with new intercooler and piping and maybe a 91 octane and E-85.

So any input on why AFR are so lean suddenly?

 

boost leak, exhaust leak, bad tune, fuel pump relay going out... not necessarily in that order.

 

You were definitely in a limp mode. The way you know for sure is the engine going between .5k and 1.5k RPM. The way to reset it is to turn the ignition off for at least 30 seconds. When you restart, the limp mode will have gone away, but the SES light will stay on. You will have to clear the SES light with a tool. Turning the MBC down will stop the limp mode, at least for now.

The running lean condition may be caused by a few things:

1) The fuel relay is starting to fail. Most of the fuel relay issues I have seen start at about 10k miles. Just pop in a new fuel relay and the car will richen up. There are multiple threads about it.

2) Because you ran more boost than normal, you may have been hitting higher load cells in your fuel map and your tuner may not have interpolated all the way out. I am not saying your tuner messed up, it may need to be checked.

3) You developed a boost leak by running the higher boost.

Getting rid of the MBC and going to a 3 port is a great suggestion by Goofygrin. I think you will be pleased with the results and the ability of the 3 port to control the turbo. Don't just buy one and plug it in, however. You will have to be tuned for it to work properly. If your tuner left the stock wastegate tables in, there will definitely be a problem.