348 CEL's

Perhaps the connectors that go into the power modules?

http://ferrarichat.com/forum/showthread.php?t=58847

 

The connectors for the lambda (O2 sensors) are located under the air box. I would check to see that you don't have any broke wires on the back of the connectors.

The other thing you can do is run an additional ground wire from O2 sensor to the frame. This has worked for others in the past.

 

Ya know... I didn't even read that about the Lambda code until just now... ignore my post, it's worthless crap.

 

Try checking the MAFS connections also.

Electrical problems are the BIGGEST pain in the neck with Ferrari's. It's sounds like what ever you unplugged the car didn't like it. The lambda is basicly the stuff controling the emitions of the engine. Those would be the oxygen sensors, and the mass air flow sensors.

Try this.

Swap the O2 sensors from one side to the other, then run the car and see what happens.

Then check the resistance on the MAFS. This thread discusses what to do http://ferrarichat.com/forum/showthread.php?t=20378&highlight=MAFS+adjustment

But more than likely you have a connection problem, where the signal is not getting to the motronic ecu. This is either cause by a bad part, or a poor connection. That is why you are getting the codes. More often than not the problem with these cars is a bad connection. Be it a dirty connection, busted wire, loose connection, or even a bad ground.

I feel your pain. Electrical probems SUCK NUTS.

 

If I remember correctly, your lambda circuitry only kicks in when your car is hot **and** you aren't at Wide Open Throttle.

So you seem to be saying that you are fine right at first when the car is cold...but then goes haywire when the O2 and MAF's start to matter (i.e. car is hot).

So I'd think that either your O2 or MAF connections are bad or unplugged or broken, or that the MAF filaments are covered with your contact cleaner.

348's have self-cleaning MAF filaments, but that self-cleaning operation may take many drives to work (operates at shutdown after car has been driven for 15 minutes or so).

Anyway, our 348's basically have 3 levels of operation: cold, warm, and warm at wide open throttle.

It's only that middle level where our emissions gear is fully working.

There are also two cold-start valves that close when warm. Other than that, our cars run the same hot or cold (which is to say, they don't run in the same way at all).

 

Lambda regulation just refers to the fact that the sensors are going full tilt to regulate fuel mixture and it's still not enough. I would unplug them and run the car to add to the data base. If the car runs normally then something in the O2 system needs to be considered. If on the otherhand if it persists we can consider the code a sympathetic action.

Another thing that has not been mentioned is a problem with the coolant temp sensors. Way too many times I have seen a broken wire at that connector cause similar symptoms and it would also cause a Lambda regulation code.

An open connection or high resistance at the temp sensor will make it very rich. Something it can tolerate when cold but less so when you get some temperature in the motor.

 

Yeah I got it smogged. What that problem turned out to be was a hollowed out cat. I finally ended up spending the coin to have a mechanic get it to pass. Yes he did it with one working cat. He also wouldn't give up the secret as to how. So no new magic trick for me, LOL.

They were fine.

By using the mixture screw on the MAFS. If you look at the picture in the thread I refered to, the screw is under the red button.

 

This sounds like a connection problem. I have had my 348 for 16 years and early on I had to clean and fix several connections, and there have been zero warning lights, etc for 15 years. Those connections are pretty sensitive.

Incidently, you don't have to remove the airbox to remove the oil filter. Its a little tight, but you can get the filter out fairly easy.

Best of luck w/those connections.

Ciao