My s4 is running rich and I was wondering if there were any ways to lean out the fuel mixture a bit.

 

i used to think the mods were ***** always complaining about people not searching, but i'll be god damned if they arent 100% completely accurate

 

ONLY at idle by using the Variable Resistor. It's shown in the online fsm in the FUEL section. Series four only.

That and making sure your water thermo sensor is connected.

Or you could buy a Wideband Sensor and kit and a SAFC to go with it and use the SAFC to lean the mixtures out. SEARCH for WIDEBAND. Costly. Probably cost more than most these cars are worth.

 

How do you know it's running rich? You've given us zero info about your car and any problems or symptoms you're experiencing. Is it running normal rich factory mixtures or abnormally rich mixtures indicating a problem somewhere?

Forum hint #1: Ask a complete question and you'll get a complete answer.

 

I know its running rich because I can see smoke that smells like fuel coming out of the exhaust and the spark plugs have a lot of carbon build up on them.

 

So you're rich at idle. That's pretty normal, and it doesn't mean you're running any richer than normal when driving. Has performance or fuel consumption changed? Do you see black smoke while accelerating? How old are those plugs?

 

Alright thanks.

 

The plugs are new.

 

Some times I can see some black smoke.

 

Well, you cant adjust anything other then IDLE richness unless you get aftermarket fuel control.. SO there we are.

 

Alright then, thanks guys.