Sudden Lumpy Idle and l=Lots of Codes!

[Graverobber]

Backstory: I have a 2001 986 2.7, which recently required the replacement of all four O2 sensors due to degraded emissions performance codes. Upon removal of the rear two—the ones that matter for getting the car smogged—I found that someone previously had silicone-sealed the connectors, causing a devil of a time to disconnect them. When I finally got them replaced, I found the car had a new code—P1117—indicating that the #1 bank O2 sensor's heater wasn't functioning to the car's liking.

Here's where things get weird.

I went and re-cleaned the #1*back O2 sensor connector and, with the key on, ran a pigtail from it so I could confirm that it was getting voltage, which it was. I put everything back together, and when I fired the car up, it went into a hunting idle and had absolutely no throttle response (EGAS) at all. I have a Foxwell scanner with Porsche-specific code reading capability, so I did a scan, and while the P1117 code is gone, it came up with a bunch of new codes:

P1219*Accelerator Pedal – Signal Implausible
P1578*Accelerator Pedal Potentiometer 2

P0121 Accelerator pedal potentiometer 1

P1121 Throttle position sensor 1

P1122 Throttle potentiometer 2

P0103 Hot film MAF sensor

P1601 CAN Timeout - instrument cluster (the trip odometer mileage did reset to zero)

I have attempted to recalibrate the throttle (60 seconds on, 5 off, 15 on, 5 off, then start) and have tried disconnecting the battery for a few minutes. Nothing has brought the car back to running properly. It ran without issue before unplugging, cleaning, and re-plugging the O2 sensor. I am at a loss as to what might have happened and what's causing this slew of codes and the bad behavior. On the plus side, the O2 sensor seems to be working!

Any help on what to do next would be greatly appreciated.

[JFP in PA]

You have a litany of electrical related codes, most notably the CAN bus time out, which all say things are not communicating as they should. I would start with a close examination of the wiring harness sections you just worked on...............

[Graverobber]

Yeah, I think I may have accidentally fried my ECU. I'm sending an email to ECU Repair Specialists in Florida to see if that sounds repairable.

[jklaspok]

Be careful with the "ECU Specialist". I have a 987 that had an issue with the ECU. I sent it to a specialist who determined the ECU had a few loose solder connections. They corrected the connections, but had no way to test it. The result was they fixed nothing, and I was out $200.00. I ended up purchasing an ECU of the same version off of Ebay. Good luck!

[Graverobber]

Thanks for sharing your experience. Specialized ECU Repair is the one Samcrac used for his Ferrari, so I feel a bit confident. According to their site, they have test rigs for the cars for which they offer services. We'll see what they say about my predicament.