HELP - 95 355 ECU Code 4131

If I'm not mistaken it's for the secondary air pump. This thing http://eurospares.co.uk/partTable.asp?M=1&Mo=691&A=1&B=40961&S=

 

I would probably just check the connection to that air pump. Buy some electric grease and cover all of them including o2 sensors.

 

Check the fuse to the air pump (passenger footwell), they used to blow with great regularity, until Ferrari switched them out with one that was 5 amps higher rated. Check yours, and it should be 5 amps greater than what is listed in the manual or on the fuse box lid. If not, get one.

 

Yes, replace them both...if one is going, the other cannot be far behind. What is your location? You can buy them online from Rockauto.com $166 each, ready to go. Or for $63 each you can buy the Bosch "universal" four wire O2 sensor and simply splice your factory plug onto the new O2 sensor (the Bosch universal sensor comes with the splicing kit.

I bought one locally for $75 from the local Schuck's Auto Suppy store.

 

I thought that code was for the A/C compressor signal??

 

It very well could be. I was just going off the top of my head. You know what, now that I think about it you're totally correct. My goof up, and thanks for the correction.

 

Somewhat possible...but not entirely likely.

The way to test is to floor the accelerator. 348's (and 1995 355's) ignore the O2 sensors at Wide Open Throttle, so if you get full power at WOT, but don't get the power that you should at mid-throttle, then it might be an O2 sensor...

 

No worries. I was just going to update the 348 Primer if I had that code wrong.

 

If a crank sensor fails or has a wiring problem, your fuel pump on one side of the engine will quit. Then you are running in "Limp Home" mode on half of your engine.

Likewise, if a SLOW DOWN exhaust ecu signals an overheated cat, then half of your engine will be shut down.

Either problem will rapidly erode power to less than 1/2. Plus, power can rapidly come back if the systems in question deem it OK.

Do you see both SLOW DOWN lights prior to starting your engine when the ignition key is turned to Position II (run, not start)?

If not, replace the bulbs for the SLOW DOWN lights with your seat belt warning bulbs.

With working bulbs, the next time that your power cuts out, look for your SLOW DOWN lights. If they still aren't coming on, then your problem is likely with your crank sensors, instead.

 

Swap both O2 sensors from one side to the other and see if the problem jumps sides?

 

True...

 

Absolutely do this. I have spent a bit of money on parts that were not the problem by omiting this step. I think you have either a fuel or spark issue, not a mixture issue. So I would definitely swap the sensors before wasting money on the o2 sensor.

Also, in my limited experience (o2 sensors and MAF sensors), generic sensors will generate generic results. It hurts to pony up, but I'd recommend the Ferrari parts (www.ricambiamerica.com). But I think you will looking at other things...

I got my fingers crossed you sort it easily and soon.

Cheers,

-J.

 

You can swap ECU's side to side also.

 

I called Bosch tech support about O2 sensors a couple months ago. The tech told me that what differentiates the various O2 sensors that Bosch makes are the following:

1) Threading on the unit.
2) Whether it is a one wire, two wire, three wire or four wire type
3) Length of cable
4) Type of plug on end of cable.

So I asked him if I needed a pre-cat 02 sensor immediately for my 97 355 spider, which would I use and gave him the Bosch oem part number...he gave me the equivalent four wire Bosch "universal" part number, and said it will work fine, and the only difference would be that it comes with extra long cable leads, and a splicing kit.

I went to the local Schuck's Auto Supply and bought one for $75. Removed the old one, and snipped off the plug and a few inches of the cable bundle. Then shortened up the cable on the new universal unit, and rather than use the crimp type splicing kit that came with the new O2 sensor, I soldered all the splices and then sealed them up with heat shrink tubing (individually, then one large peice of shrink tubing for the entire four wires). Plugged it in, and had the code cleared, and two months later, still working great. Looks stock too.

If you don't want to go to all this trouble, then by all means buy the oem Bosch unit with the correct length cable and plug, ready to go. Daniel at Ricambi has excellent prices on them, I have bought one from him before!

 

Swap the mass airflow sensors (Dual on '95's) from side to side, and see what happens. Takes 5 minutes to do. See if the code jumps banks or goes away do to reseating the MAF plugs.

 

The Mass Air Flow Sensors are located between the intake opening and the air filter boxes. Have a good look at the connections to make sure everyting is clean and connected properly. Be sure that there are no signs of busted wires under the rubber boots for the connectors.