355 Code P1448 Every 50 Miles

Anything you did different, or just some good luck?

 

Swap your CAT ECU's around and see if the code changes. It may also throw a SDL light if it's the ECU being bad after swapping. I was able to identify the bad ECU on mine this way. All 3 are the same so you can move them around to see if the problem moves with it. The bypass and passenger side CAT ECU are behind the passenger rear wheel next to each other. You can simply swap all the plugs from under the car on the ground (mark them to keep track first). If you need to replace the ECU a 2nd set of hands makes it a pain to a breeze to get the bolts.

 

Most of those are O2 sensor related. Enough codes that something major is off. Like a major harness is disconnected. Did you unplug anything while it was running? Or forget to plug something back in while poking around?

 

Easy enough to google them - they are O2, evap and engine temp related. Is one of your wire harness unplugged?

 

Some of those i would think would show right away. How is it running? I'd clear them all and see if they immediately return. Is there a chance they were stored codes from some troubleshooting prior and the 1448 just popped back up finally? Were they full codes or pending?

 

I'd have it looked at. Something isn't right.

 

As mentioned elsewhere, no one has F355 5.2 diagnostic codes, but using F360 codes

P0160 Left downstream catalyst O2 (no activity detected)
P0140 Right downstream cat O2 (no activity detected)
P0154 Left upstream cat O2 (no activity detected)
P0134 Right upstream cat O2 (no activity detected)
P1448 Exhaust bypass circuit
P1121 Left downstream O2 sensor heater (short to ground)
P1117 Right downstream O2 Sensor heater (short to ground)
P1119 Left upstream O2 sensor heater (short to ground)
P1115 Right upstream O2 sensor heater (short to ground)

Oddly, P1121 is the RPM Sensor on the 2.7 car.

Fuse 22 in the footwell provides power for the O2 heaters. I would check fuse 22, maybe a short has blown the fuse.
The ECU provides power for the O2 sensor elements. I don't know if the "no activity detected" is related to unheated O2 sensors (during warm up). Activity may or may not be monitored during warmup (for messaging purposes). The ECU turns on the heaters. I don't know what tells the ECU to turn on the heaters. Water temperature?

Code P1448 (Exhaust bypass circuit) is probably your old problem.

Sorry, more questions than answers

 

Under the footplate on the passenger side.

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https://www.ferrarichat.com/forum/posts/141359922/

hinges at the bottom, two fasteners at the top.

There are a few other goodies in there... Bilstein suspension unit, doorlock module, fuel level damper, etc...

 

I would keep an eye on the fuse. You may have an intermittent short in the engine harness. Sometimes there is improper routing of the O2 sensor wiring and it touches hot engine parts. The insulation may have burnt through.

 

No, extenders would not cause those codes

 

Not directly, but maybe the guy who fitted the extenders didn't route the wiring for them properly?

 

The 2 white wires are the heater wires. You can unplug the sensors one at a time and check the resistance between the 2 white wire to check the heater. It should be between 5 and 10 ohm or so. If zero or very high, the heaters are shot and the sensors need to be replaced.

 

I've always found if the heaters are not working you will get a CE light. I've had P codes for failed O2 sensor heaters on both my 355 as well as my BMW. In other words, the Bosch Motronic monitors this for you, so testing shouldn't be required.

 

I suggested testing the heater resistance because of the abundance of O2 codes which may indicate the problem is elsewhere and the codes may be spurious.

All 4 are reporting short to ground. The heaters need to be measured to determine if the short is internal or in the external wiring somewhere.