btw, i didn't change the o2 sensors because I thought that the misfires might have thrown the o2 codes. They didn't come back when it lost all power, but they did later in the day when it lost power again. I can't think of what it could be.

 

Also forgot to mention that the EPC light comes on when it happens, but no check engine light. Any help would be appreciated.

 

Ok, I took out the MTM ECU and put the stock ECU back in and ran it for a few minutes this morning. It won't lose all power like it does with the MTM ECU, but it doesn't feel nearly as powerful as it should below 3k rpm. I read the codes out when I got back. They are:

3 Faults Found:
17965 - Charge Pressure Control: Positive Deviation
P1557 - 35-00 - -
17539 - Oxygen (Lambda) Sensor: B2 S1: Internal Resistance too High
P1131 - 35-10 - - - Intermittent
17521 - Oxygen (Lambda) Sensor: B1 S1: Internal Resistance too High
P1113 - 35-10 - - - Intermittent

Questions:

What is the charge pressure control: positive deviation?
What o2 sensors are bad? I take it bank 1 and bank 2/ sensor 1 on both?
If the guy who had the car before me did piggies, would this throw the o2 codes?
Why would the car almost cut itself off with the MTM ECU and not with the stock ECU?

I also noticed that when I was hard on the throttle and it "missed" it sounded like I had a blowoff valve, just not quite as loud. Does that mean one or both of my diverter vavles are bad and how do I check them?

Sorry for all the questions, but thanks in advance for your help.

 

Kind of still sounds like a massive boost leak to me, perhaps even out of a diverter valve itself.

Better get your intake system properly pressure tested.

 

Thanks for the reply. The thing is, I logged the boost and it seems to show a small boost leak, but nothing major. I'll try to get the graph up a little later.

 

Still looking for some answers. I just don't even know where to start. I have an excel spreadsheet of two boost logs I made earlier in the day if someonewants to give me some help, I can email them.At times, the car is overboosting, but most of the time it is underboosting. Obviously a boost leak, but why would the car be overboosting? Also, why is my computer (stock ecu) requesting 1610mbar at one point? Isn't that equivalent to about 23 psi? Need some help..