Which O2 sensor is bank 1?

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jseabolt
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Which O2 sensor is bank 1?

Post by jseabolt »

The check engine light came on my 03 Baja this morning all of sudden. So I diconnected the battery for about an hour and it reset the light but it came back on. So I went to Advance Auto and the guy hooked his code reader up. It's saying the O2 sensor on bank 1 is bad. He ordered me a new one and I'm going to replace it myself but he says it's "bank 1". So is bank 1 the upstream sensor or the one in the converter?

Thanks.
http://s222.photobucket.com/albums/dd148/turbofiat/

2003 Subaru Baja
1968 Ford Fairlane 500
1980 Fiat 124 Spider (turbocharged)
1987 Yugo GV (1500 turbocharged)
1981 Trabant 601 S
1987 Citroen 2CV
1977 MGB
Zooom
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Re: Which O2 sensor is bank 1?

Post by Zooom »

no sure which would be bank1, but normally, Bank 1/Bank2 for this specific discussion refers to a left or right sensor if you have a split header. Upstream(front) or Downstream(rear) would refer to in front of the Catalytic Coverter or after it.....

on the Baja, I would bet it'd be like other manufacturers with 2 cylinder heads, that Bank 1 (meaning bank of cylinders) would be off the cylinder head that contains cylinder #1(See- firing plug order for clarification, not sure if it the left head is #1 & #3 or if it is #1 & #4 or what) and the apposing head would by default be Bank #2.

hope this helps.
Nitro350Z
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Re: Which O2 sensor is bank 1?

Post by Nitro350Z »

Guessing you got a P0030 (or P0031/32) code? That would be your front O2 sensor. I had a P0032 code not long ago and switching out the front O2 sensor fixed it. It was an easy job, took ~10-15 mins to swap it out. If you could get us the exact code you have, it would help.

The part number is 22641AA280, I bought mine from SubaruParts.com. They were the cheapest that I found for an OEM replacement. The grandforks dealer wanted around $200 usd for it and a local dealer wanted 320+ cad.
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jseabolt
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Re: Which O2 sensor is bank 1?

Post by jseabolt »

Nitro350Z wrote:Guessing you got a P0030 (or P0031/32) code? That would be your front O2 sensor. I had a P0032 code not long ago and switching out the front O2 sensor fixed it. It was an easy job, took ~10-15 mins to swap it out. If you could get us the exact code you have, it would help.

The part number is 22641AA280, I bought mine from SubaruParts.com. They were the cheapest that I found for an OEM replacement. The grandforks dealer wanted around $200 usd for it and a local dealer wanted 320+ cad.
Fixed it! It was apparantly the front sensor. I had to take the car back to Advance Auto to have them to kill the check engine light but so far it has stayed off. I guess I could have unhooked the battery again but I didn't like having to reset my radio presets and wait 30 minutes again. Plus they sold me the sensor so they could have least kill the code for me.

When the guy said "bank" I was under the impression there might have been a sensor for each exhaust manifold.

Here's a tip I found on another website which sort of makes it easier if you don't have a lift since I've yet to figure out a way to lift the entire front end off the ground with a single floor jack. Remove the passenger side wheel.

Figuring out how to unhook the sensor from the connector was probably the biggest hassle. I used a small flathead screwdriver and inserted it into the slot and kept working at it until I was able to unplug it.

This is the first "problem" I have ever fixed myself where the check engine light kicked on.

I had a Chevy Cobalt once that the check engine light kicked on after it sat for a few weeks. That turned out to be a corroded connection at the sensor that tells you, you left the gas cap off. Nothing wrong with the sensor. It was just sending a false signal to the computer. I had no idea where to even start looking or how to test the component.

Before buying my Subaru, I had a Jeep Wrangler with a weird intermittant starting issue. Chyrsler said it was a bad crank sensor but 6 months later the problem came back. The check engine light never came on but the computer flashed two codes. Battery recently being disconnected and a problem with the Air conditioning. Yet the vehicle didn't have A/C and I had replaced the battery awhile back! So I sort of lost faith in check engine lights and warning codes.

WOW! Just $129 + shipping? If snow season was over I would have waited and just ordered one from Subaruparts.com. I paid $200 with tax for a Bosch sensor from Advance Auto.
http://s222.photobucket.com/albums/dd148/turbofiat/

2003 Subaru Baja
1968 Ford Fairlane 500
1980 Fiat 124 Spider (turbocharged)
1987 Yugo GV (1500 turbocharged)
1981 Trabant 601 S
1987 Citroen 2CV
1977 MGB
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