HELP! Lots of o2 codes.

**JackieTA** · 06-14-2015, 08:30 AM

Here are the codes:
P0131- o2 sensor circuit low voltage. Bank 1, sensor 1.
P0151- 02 sensor circuit low voltage.
Bank 2, sensor 1.
P0174- bank 2, system lean.
P0300- multiple misfire.
P0463- fuel level sensor
P1153-heated oxygen sensor insufficient. Bank 2, sensor 1
P1380- misfire detected rough road.
P1637- generator terminal circuit.

Runs great above 3000 RPMs. Dies at low RPMs. Dumping gas out the exhaust. Any advice? Just got the car.... Can't even enjoy it.

**pajeff02** · 06-14-2015, 01:25 PM

Welcome to the site!

Sounds like maybe some wiring may have gotten fried on the exhaust... but here are some other possibilities:

Fuel pressure issue, dirty or defective MAF, exhaust leak that is allowing air to enter the system above the front O2 senders, defective O2 senders, or a substantial vacuum leak. Is everything stock under the hood?

**JackieTA** · 06-14-2015, 03:07 PM

It has headers and 3" exhaust. I don't know of anything else. The previous owner died, so I'm clueless on the history of the car.

**pajeff02** · 06-14-2015, 04:36 PM

In stock configuration, your car has four (4) O2 senders, two on each side, also known as "Banks". Bank 1 is the driver side and Bank 2 is the passenger side. The pre-cat O2 senders are what help control fueling while the post-cat senders simply tell the PCM if the cats are doing their job. The post-cat senders have absolutely nothing to do with fueling.

A car that has been outfitted with headers is a prime candidate for cooking through the wiring, or having O2 wiring issues. If you can access the underside of your car, you will find the O2 senders mounted in the collector of each header - those are the ones that control fueling. Carefully check to ensure that they are plugged in and then trace the wiring back up as far as you can. Look for burned or melted wiring and also inspect the connectors for corrosion or any bent pins.

With headers, the prior owner either installed senders with a longer wire harness - like Bosch P/N 13111 senders, they installed an extension harness to make up for the needed length, or they spliced the wiring together. The last method isn't a good idea and could be the cause of your issues. Take a look under your car and let us know what you find. Also, if you can post pics that would be helpful.

**pajeff02** · 06-14-2015, 04:53 PM

Here's an older shot from under our car. You can clearly see the pre-cat O2 senders mounted in the collectors. Note that our car has the rear O2's deleted and that those sensor mounting holes are plugged.

**0rion** · 06-16-2015, 09:18 PM

that's a shit ton of just random codes there.....makes me thing like Jeff and it's a harness issue or perhaps corrosion on the pcm plug pins or something. Easiest thing is to start by chasing those wires dropping down by the headers to make sure they're not melted or spliced all to hell or something. Then pull the plugs off the pcm and look in there for corrosion. Next I would probably start looking at the grounds on the back of the head.

**pajeff02** · 06-17-2015, 02:50 AM

Just for giggles - also check your "ENG SENS" fuse in the underhood electrical box.

**JackieTA** · 06-18-2015, 11:43 AM

PCM Pins? I don't know what those are. I bought two Bosch 13111 o2 sensors, but haven't installed them yet. A fuse sounds way too easy, but I'll definitely look at it!

**0rion** · 06-18-2015, 12:25 PM

seems your O2's could cause most of those codes...the misfire rough road is a pretty random code. I've never even seen that code thrown before along with the generator code and fuel level sensor code. The rest and maybe even the rough road can be explained away with bad O2's.

**pajeff02** · 06-18-2015, 12:39 PM

PCM = Powertrain Control Module. It is tucked into the back passenger side of the engine bay and you'll see two large harness connectors bolted to the module. On occasion, the pins in the connectors can become damaged or corroded and can cause a plethora of issues. It doesn't help that the General mounted this box right at the cowl where water can potentially get to it.

**JackieTA** · 06-18-2015, 10:55 PM

It's fixed! I replaced both o2 sensors and it ran great on a 30 minute test drive. But my o2 sensors are smashed up against the transmission fluid pan (passenger side) and hitting the shifter linkage on the drivers side. Will this ruin my new sensors? The wires are almost at a 90* angle because they are against these things. Is this something I should be worried about? Do the sensors need to be moved forward to get more clearance? Also, catalytic converters are gone, holes plugged. Thanks for all the help. Great website!
PS-previous owner had spliced the wires on the old o2 sensors.

**pajeff02** · 06-19-2015, 10:18 AM

It is likely that you will be having the same issue down the road unless you modify or relocate the sensor bungs. Two choices: First, you can install plugs in the existing holes and weld in new bungs. If you do this, you want to make sure that the sensor is mounted at 90 degrees or above so that the tip (inside the exhaust pipe) points downward. Second, you can remove the sender, thread in a long bolt and then heat the pipe with a torch until you can bend the sensor bung into a slightly different angle for added clearance. Just be careful you do not accidentally tear the pipe or melt it.