Hey guys. My brother was driving my car yesterday and the in the middle of driving the CEL came on and the cruise started to flash. The car appears to be driving normal he says. He tried to hook up a scan tool to it but it says no communication with the ECU. my mods are:
FP Green
UTec
Modded Injectors
Walbro 255 Fuel pump
Turbo Xs intake
Turbo Xs FMIC
Turbo Xs Dual Stage Boost Controller
Godspeed DP
HKS Carbon Ti Catback

Any reason why the ECU would not communicate with the scan tool? He tried it a few times and made sure the connection to the OBDII port was secure. I am not in town and the only thing i can do is give him suggestions. Do you guys suggest anything?

keep trying to pull the code.

what do you mean by keep trying to pull it. Keep on connecting and disconnecting it? Everytime it says no communication.

You hit either a Fule Cut or boost cut, a hard one infact and it is letting you know that something happened. I dont think there is a code associated with it as it happened to me back in my pre tune days.. Just reset the car by pulling the negative cable on the battery and pump the brake a few times to discharge static in the car. Go and drive the car somewhat spirited and see if you can replicate the problem then post where it happend and at what RPM and MPH... then we can get more answers from there

he resetted the car and the code is gone now. He is going to drive it around and see if it comes back on. Still though why would not the car communicate with the scanner though?

You hit either a Fule Cut or boost cut, a hard one infact and it is letting you know that something happened. I dont think there is a code associated with it as it happened to me back in my pre tune days.. Just reset the car by pulling the negative cable on the battery and pump the brake a few times to discharge static in the car. Go and drive the car somewhat spirited and see if you can replicate the problem then post where it happend and at what RPM and MPH... then we can get more answers from there

he says he did not take it over 4k rpms.

Try the scan tool with the car running, I clear codes that way it might help communication. Just a suggestion.

he tried plugging it in while the car was running as well and he got no communication.thanks but any other suggestions?

Mine did the same thing with the GPmoto headers and APS TBE w/o cat during normal driving at @ 65 in 6th gear at highway speed. Drives normal just researching this problem now until I get my AP to check the code.

what i am guessing is that my downpipe has a trick o2 bung with cat material so it prevents the CEL to come on. When i took the downpipe out last, i remember that material in there falling apart hence not really tricking the ecu. I put it back together and the CEL dident come one. Its been about 1000 miles since then so im guessing that its throwing a CAT efficiency code.