-No check engine
-No smell from under hood or under car only from my muffler
-When im cruising on freeway car back fires when i let off and on gas (not everytime but here and there <straight pipe>
-No check engine

Car is tuned & these are recent symptoms ,

 

I assume you are on OBD2. since you are in CA and any other OBD would be illegal, in which case you could take to get it scanned, and even do a real-time driving log. One would think you'd have purchased a scanner for your modified vehicle already though.

 

Obd2 Cant be tuned , And i live in cali i dont drive like a jack *** to get my car taken away

no check engine nothing for me to scan

 

Ecu?

 

other then smell car drives normal to me just stinks ....it was doing fine for awile im going to change my spark plugs they havent been changed

 

SCANNED not tuned.


You can scan it for most recent fuel tables, you can also do diagnostics while driving it. It tells you what the engine is doing so you can get an idea where the problem is. Also you can have codes without a check engine light.

Find someone that has a data-logging scanner and drive it while hooked up. Alternatively you could get Torque (Android app) and the bluetooth dongle to go with it and figure out where the issue is on your own.

This is the whole reason why OBD2 exists, so you can do live diagnostics.