2 AF sensors, Code P2237, and still the check engine light is on...

10 days ago the CEL illuminated in my 2008 Touring. I took it to our usual mechanic, he checked the code, and it came up with P2237, which he said indicated that the Oxygen sensor needed replacement. Picked it up that afternoon, and just as I pulled out of the parking lot, it came on again. Not fixed! He cleared & checked the codes again and ordered a second sensor, thinking the first was bad, too. Fixed, he said! Same thing. Started it up, and on came the light. So....he refunded my money, put the original sensor back in, and suggested I go to the dealer. Ugh. Any thoughts? I didn't see this particular issue when I searched the forums, but if it's out there, if someone would just direct me to the proper thread, I'd appreciate it. I want to have some knowledge when I speak to the service guy at the dealer.

Thanks!

 

Thank you. Yes, the receipt says Bank 1, Sensor 1. Where would I find the fuse?

 

Thank you, he did mention something about the relay, but wasn't able to fix it for some reason. The code is definitely P2237--he showed me. I will see if the dealer concurs with one of these possibilities. Hopefully, this won't be too expensive!

 

Both were from Toyota. Looks like it must be some other component of the system--wire, relay, fuse...

 

Update: I live in Northern VA, so I took it to the closest dealer. Sigh. Told the guy who made the appointment and the guy who checked it in what had already transpired (oxygen sensor replaced twice, light still on, must be relay, wire, fuse, something else). When the service guy finally called me at 7 pm ( I left the car at 8 am) he said he wanted to replace the oxygen sensor. Why am I surprised? When I told him the story, he said it was the first he'd heard of it. No one had related what I told them to him. Of course not. But he still wants to replace it and see for himself. Fine. Two more days pass, and they replace the sensor, clear the code, and the CEL comes back on. Back at the beginning again. They call and want us to authorize 2 hours of labor (at $100 an hour) to try to figure out what's wrong. Seriously? I want to scream. Instead, I let my husband deal with them, and he agrees to the 2 hours, but I tell him I am NOT paying for the oxygen sensor. They can take it back out. You would think in the DC metro area there would be someone who could work on my car other than the dealer, but I can't seem to find anyone. Service at The dealer is the WORST. Meanwhile, I have no car and I have to get the emissions inspection next month or I'd just walk.

 

After 4 days of looking for the problem now The dealer wants to replace the wiring harness at a cost of $1800, plus the $215 we've already racked up in labor costs to try to find the problem. Fix it or not?

 

Thank you. Not a DIY-er unfortunately! The dealer did admit that it was likely only one wire, but said it would cost more to trouble-shoot each wire in terms of labor ($107/hr) than to just go ahead & replace the entire entire harness. Just seems expensive for wires... Maybe I will call our usual mechanic & see what he thinks. Thanks again.

 

Update: Itell the dealer to just put it back together. I don't want to spend $2000 for the wiring harness without a second opinion (on the price mainly!). Picked up the car Thursday night, after some heated discussion about the charge. It ran fine and the light was off. Drove about 35 miles, still no light. I'm wary, but happy. The next morning I get in and push the button, and every warning light known to man comes on...red triangle, car with exclamation point, circle with exclamation point, check engine, and I don't know what else. Car starts briefly, but stalls if I try to put it in gear and move forward or back. The battery indicator shows it's drained, just a purple line. I call my regular mechanic who says it sounds like the battery, which should still be under warranty, so try to jump it and take it to the other dealer in the area. I call for roadside assistance. They try for 45 minutes to jump it, but it won't start. I have it towed to the dealer, give them the synopsis of the past two weeks events, and they check it out and call me with a diagnosis of the ECM. $1300. They say this will fix the prior issue, as well, no wiring harness. I know the ECM was one possibility from Parick Wong's reply, so does this sound like a reasonable diagnosis?

 

No, they won't install a used one & I am not under warranty (2008 with 90,000 miles). My regular mechanic said it wouldn't be much difference in price if he did the job ( with a new part), and since it's not driveable, that would involve another tow. Not sure I have it in me to deal with that. Geico sent the Three Stooges out fir tge first tow. Yikes! Thanks for the advice, though. I appreciate it!