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240 error codes

3616 Views 4 Replies 2 Participants Last post by  swedish wagon slayer
I posted this under maintance, but thought I would try here.

Ok, I had high NO on my ca smog. I now have check engine light on with the following error codes in this order.

2-3-2: Fuel system compensating for rich or lean mixture at idle
2-3-1: Fuel system compensating for rich or lean mixture a cruise
2-2-1: Fuel system compensating for extremely rich or extremely lean running condition at cruise.

Any ideas where to start?

So its lean it seems like. Computers, MAS where changed. They could have gone bad I suppose. Done before I bought the car. Really at a loss to where to, or, how to start looking. Any help would be a blessing............
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Assuming those things you listed are good, it could be a faulty Fuel Pressure Regulator allowing too much fuel into the injectors possibly. He is a how-to to check that from Default

A fairly easy test to see if the FPR is pressuring up too much requires disconnecting the fuel return line (back to the fuel tank) from the rear of the fuel rail. On my 940, this is a simple hose clamp. Be prepared for some fuel to spill. Now get several feet of rubber fuel line hose, slip it over the open end of the fuel rail, and aim it into a gasoline-safe container. Have an assistant start the car, and observe the fuel flow from the hose. You should get a strong stream of fuel, something on the order of 1/2 to 1 gallon per minute. If you get just a trickle or no fuel at all, the FPR is bad. [Tip from Mark Lundell] When you replace the FPR because of a rich burning problem, also replace the little vacuum tube and clean out the intake manifold nipple.

A bad MAF can cause such symptoms as well, but the car would run extremely poorly if at all. A bad ECU can put the wrong amount of fuel into the system too. Might also have a bad Engine Coolant Temperature sensor that goes to the ECU.
I would check this out and go through some of these steps Engine Tune and Performance
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Well ok. Its been acting funny. The Problems rotate around. Same thing, just not everyday the same thing. They take turns (how nice that they share). Keeped digging and found the PVC hose to the fire trap split. TOTALLY missed that. HUGE vacuum leak! Ordered a new one. I am going to replace all the hoses and fittings, including the trap. I will report back what I find after the parts arrive and installed.

Air after the MAF equals more air that the ECU doesn't know about, equals why I have my error codes of lean mixture.
Well, that help a little, but still registering errors. I'm starting to think that either the MAF or the O2 sensor might be out of tolerance.........
After many bouts with the beast, I slayed that problem. MAS! Replaced it, and runs great.

Now it stalls, and I have to pull the #4 fuse to get the fuel pump going again. Going to look at the relay first. If that's OK, I'm thinking it is the pre-pump.

Any thoughts out there?
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