Plugged a Mac Tools reader into the car and came up with this code:

P2A00 O2 bank 1 sensor 1 range/performance

It's an '05 Civic HX 5-speed.

The engine accelerates fine, idles fine, but it takes a few extra seconds to start up and it dies during cruising speeds. Once I let off a bit on the pedal to maintain speed, it loses power and I have to downshift to keep it moving.

Since it's the lean burn model, my guess is the O2 sensor is bad and it's screwing up the air/fuel ratio when it goes into lean burn mode?

Either way, should this simply be replacing the O2 sensor? If so, which one? The one on the manifold seems to be the typical 4-wire unit.

Thanks for any help!

 

The code and symptoms point to a bad O2 sensor or wiring to same loose/disconnected. Check wiring. $230 for OEM online at bkhondaparts.com. densoproducts.com says part number is 234-9005; $100 at Amazon before shipping cost. NTK part number is 24665 and costs about $162 at Amazon before shipping. Get Denso or NTK; they are the OEM maker. Soak old sensor threads in PB Blaster for a day (during which you do some driving), then remove with proper O2 sensor wrench.

I have bought two Denso O2 sensors and one NTK O2 sensor from Amazon and all has gone great.

O2 sensors do not last forever. Five years is a decent life, though I would be doing a tuneup with OEM parts (plugs, air filter, etc.).

A bad O2 sensor can degrade the catalytic converter. Watch your next emissions test carefully.

My 03 Civic's original sensor was marked with the NTK insignia.

 

Thanks for the reply. How do you know which sensor? Just looking at autopartswarehouse I see 22 results for the hx anywhere from like 30 - 300 bucks??

**I understand you showed a few different part #s and places to buy, I'm just curious how you know which O2 sensor esp due to the big difference in price, wires, brands, etc.

 

upstream and downstream
sensor1-before cat
sensor2-after cat
i think

 

The OEM service manual, emissions installation section. If you do not have a service manual, google for {"bank 1 sensor 1" means}. Like switt wrote, sensor 1 is the upstream sensor.

I just checked autopartswarehouse and see that there are a number of upstream sensors with the proper connector (so no wire splicing needed) going for under $100. None of them are Denso or NTK. The info on the sensor must indicate that it is either an "a/f sensor" or "wide range." This is a new design of sensor. Many of the aftermarket stores seem to be selling people the old design of sensor, which is narrow range and will not work exactly right. Here is a description of the design differences between narrow and wide range sensors: http://www.autoshop101.com/forms/h37.pdf

You can remove your old sensor and check for the manufacturer's name on it. I know Denso sensors typically have the ND (for "Nippon Denso") printed on the sensor.

From my reading anything other than Denso or NTK for the O2 sensor is a gamble.

I personally would go with the $100 Denso sensor at Amazon.

 

Ok great - thanks for the help!

I've noticed that with the HX - they really didn't make that many of them. I really like it though - except for the no A/C issue.

 

You're welcome. Last year when I was shopping for a one-owner used car, I became smitten with a 2001 Civic HX coupe. It was really attractive, body-wise. It got sold very quickly.

 

Just looking around I saw this:

http://www.autopartswarehouse.com/sk...etrain#reviews

Normally I'd go OEM but with the vast difference in price and all the positive reviews I'm looking to go this way - would this be the correct upstream?

It's even $28 on a few other sites. I'm good with splicing, I'd just need to make sure it's the right product.

Thanks!

 

(After more study -- ) It seems autopartswarehouse is selling narrow range sensors for the front sensor. But it should be wide range. Narrow seems to work but poorly.

I am not sure universal fit (meaning splicing required) 4-wire aftermarket sensors exist yet for the wide range sensors.

Be careful about connecting the right wires. Connect the wrong ones, and you will destroy the sensor. If it is not clear which wires to connect, research more. The question of which wires to connect, given a universal O2 sensor, comes up often here.

If you do replace your front O2 sensor, and you can inspect it, I would be interested to know whether you see any indication that it is Denso or NTK. Thanks!

 

Will do - thanks for all the advice.