Code P2270

[MikeD2]

Hi Guys, 2004 Duratec, 151,000 miles. P2270 showed up the other day. I looked it up & it shows: Downstream Oxygen Sensor, Bank 1.

My question is, when I look up the part several of the online stores say "2 Required". Is that assuming you should change both Downstream Sensors? As far as I know, none of the Sensors have been touched before. I don't mind spending the money if that is the correct thing to do. Also, I don't want to waste money.

How hard are they to change, PB Blaster the night before? Any special sockets required?

Anything else I should know? Thanks!!

[shorod]

An O2 sensor that is slow to respond could cause this code. If you plan to keep the car awhile it would not be a waste of money to replace the oxygen sensors. At a minimum, you'll probably get your money back in a year or so just from the increased fuel economy (depending on how many miles you drive a year). I wouldn't stop at just the one sensor but would suggest you replace all 4 sensors.

Yes, they can be in there pretty tight. Using a penetrant the night before would help. There are special sockets designed for removing O2 sensors and I would recommend you get a set that has a couple different varieties of sockets since clearance can be an issue. Your local parts store might have a Loan a Tool program where you can borrow the "sensor and sending unit socket set" at no cost as long as you return the tool.

-Rod

[MikeD2]

I didn't realize the Sensors went gradually. I thought they were either good or bad. The way the weather has been, maybe I'll buy all 4 and just change the bad one for now; unless they come off easy. Is Denso a good brand?

As usual thanks for the info Rod!!!!

Mike

[shorod]

Denso would be fine. NGK is likely the OEM for your car, so if the NGK is similar in price to the Denso, you might want to opt for the NGK.

-Rod

[MikeD2]

Rod, would you have a diagram to locate the Sensors? I can find 3 of them but not the 4th. I purchased 2 Sensors for now, 1 Upstream & 1 Downstream. Also, my code shows Bank 1. I bought 2 different types of sockets, 1 is straight & 1 offset.

I hit the 3 Sensors I found with PB Blaster. I would like to change the Sensors tomorrow or Friday dependent on the weather.

Thanks in Advance.
Mike

[shorod]

I checked the service manual for the DOHC to make sure there are 4 sensors and the manual suggests there are. There are a couple of diagrams that show the locations, but it's not horribly clear to me where precisely these are at since they don't seem like where the exhaust would be. Hopefully these diagrams help.




-Rod

[MikeD2]

Thanks for the Diagrams Rod, they show more than just o2 Sensors. I printed them out & put them in my Haynes Manual.

I struggled (working under ramps) but I managed to change out the back Downstream (Bank 1) Sensor. I can see both Front Sensors but not the Upstream back Sensor.

Previously, when I started the car I smelled fuel. After I installed the new Sensor I didn't notice the smell. The Check Engine Light remained on, still with Code P2270. I tried to erase it with my scanner but no luck. I did not yet try to disconnect the battery to erase the code, I was hoping it would go out on its own.

My son has been driving this car, he has not used it this week since I was afraid of damaging the Cat. I told him to use it for work tomorrow.

As far as the Upstream Sensor goes, I would still like to change it. It looks as though its below the rear Spark Plugs. If that is the case, I will probably need a Pro.

My son has a 500 mile round trip this weekend, I guess we'll see how the Sable runs tomorrow. I could let him take Mom's Milan if need be.

Anyway, thank you for all of your help over the years; even if it's not my Thread.