boost lagg
 

i fixed my car all i needed was a new battery but now it lags boost when u step on the gas it goes but then it bogs and it starts backfiring why

Check for diagnostic codes... If you're back firing you're running crazy rich or the timing is off... may be indicative of a knock sensor issue.

how do i check all that and were is the knock sensor located

http://www.cygnusx1.net/Supra/TechTi...ror_codes.aspx

I just saw your other thread about this matter... After replacing the turbo did you check the spark plugs for fouling and replace them if needed? Also, if the former turbo was dumping too much oil a lot may have accumulated in the IC and piping which will need to be thoroughly flushed out or it may foul new plugs.

yeah i got new spark plugs checked everything and i found out what was making it lagg it was the main relay

yeah sounds like the knock sensor i had the same thing happen to me i had to rewire the knock sensor to the ecu bad stock old wire

where is the knock sensor located

simple search
knock sensor mk3 supra
http://www.toyota-supra.info/forums/...locations.html
in our very own forum!

The N/A knock sensor is actually closer to the middle than indicated in that diagram; It's not in the same location as the GTE's rear sensor.