What up fellow tuners.
Car details:
99 LS1 ATI Procharger, 44#inj., Intercooled, A4; 5PSI Boost.
I had tuned this car about a month ago for the supercharger - car left doing about 410HP.
Customer installed the SSI Aluminum Intake manifold and a 90MM TB and came in complaining that the car was not running the same; which makes sense since the vehicle is drawing in more air. Ran the car and put out 360HP. It was hot out here in California that day but 50 hp loss was too much of a loss in my opinion.
Here is where it gets out of control I started to tune the vehicle and out of nowhere the vehicle would "Command" stoich right in the middle of my WOT run; what the hell.
Did a second pull without changing anything in the ECM and did not do it - I've never heard or seen anything like this - check out the attached runs it's mind boggling. Keep in mind that both runs are on the same tune - no changes where made between the runs.
The other issue I have with it is the MAF reading it seems to be bouncing around when boost seems to be pretty consistent.
Is this just a bad ECU?