I'm about to call Len to order up a new primary O2, but really quick, I gotta ask:


this part is gonna set me back $200, so I just want to know opinions. I'm throwing CEL code whatever (the system too lean/rich code) and the general consensus is that the primary O2 is the cause. I'm in agreement.

BUT.... before I spend the dough, (I don't have another one to try out, so I'm just willing to buy a new one) is there anything else I might be overlooking, so that I don't buy a part I don't need. Obviously I want the problem fixed, and I'm willing to pay, but if the O2 sensor isn't the problem, then this could get spendy very quick. And I'd much rather spend the money on an exhaust or something. Any opinions? Or just order the damn part and quit bellyaching?

 

Have you read the exact code? That would give you primary or secondary 02.

 

definitely double check the code. also, usually if the O2 sensor is going, you will get some odd driving issues, like hesitation or poor gas mileage. the ECU makes adjustments based on the O2 sensor readings. if they arent reading correctly, the ECU doesent know how much timing and fuel to trim or add, and you can get crappy all around engine performance. if the car seems to operate ok and still getting normal gas mileage, I would probably do a little more trouble shooting.

if the code is for the 2nd O2 sensor, it may mean your cat (if you have one) isnt working properly.

Im not sure if the search function is working or not yet, but I believe you can find other O2 sensors that will work that arent $200. It doesnt have to be a "Honda" part.

 

Yeah, I've pulled the code, I just couldn't remember which one off the top of my head. It isn't a code for any sensor at all. It's just the code that says: fuel system too rich/lean --- CEL 45

exhaust is stock, and all sensors are stock. Stock ECU, and no mods to the engine. I have been using octane booster at the pump, since where I live we can only get 91 octane, and I'm used to being able to put 93 into it.


the car does hesitate a bit, when driving in say 4th gear at 55mph and just "cruising", it will start to get erratic, then I just give it some throttle, and it eases out again. And the fuel mileage does seem a bit lower, I can't really tell, I've stopped driving the car since the CEL. And I haven't revved it past like 4 grand since. As for the part being honda, I just have heard a lot of horror stories from universal, or "cheap" O2 sensors, and I figured the Honda part would be the way to go anyway. And of course, I was given Len's number at the Acura dealership. LOL.

Does that help out at all? Think it could be something else?

 

well O2 sensors are tricky. A lot of times they are just replaced when issues cannot be resolved. Any of those symptoms you mentioned could be O2 related, but I would think you would have an O2 sensor code if there was a problem with the sensor. the erratic behavior you mentioned made me think possible TPS issue as well which I believe you can test yourself with a multimeter.

in regards to alternate O2 sensors, I didnt mean get a cheap one. But other manufacturers such as VW use O2 sensors that are like $50 and I believe they are Bosch. dont quote me on that though as its been awhile since I have researched sensor options.

Im far from an expert, but these are things worth looking into before dropping $200 on something that might not be the problem. there is a wealth of info in the archives and if the search is working I would suggest grabbing a drink and start reading.

 

I'd pull advice on what to check right out of the Helm
CEL 45:
Too Lean - Fuel pump insufficient flow/pressure
- Fuel line clog/leak
- FPR stuck open
- Fuel filter clogged
- Fuel injector clogged/air incursion
- Contaminated fuel
- Primary O2
- MAP sensor
- (if applicable) EGR malfunction
- Valve clearance
- Exhaust leakage

Too Rich - FPR stuck clogged or stuck closed
- Fuel return line clogged
- Fuel injector leaking/stuck open
- Contaminated fuel
- Primary O2
- MAP sensor
- (if applicable) EGR malfunction
- EVAP purge leaking/stuck open
- Valve clearance
- Exhaust leakage


AFAIK CEL45 wasn't used for OBD1 vehicles, so you should be able to pull a more accurate code from the OBD2 port at any parts store that offers code scanning. ie P0171 (too lean) or P0172 (too rich)

If you question and seriously suspect the O2, then connect a volt meter (or A/F gauge) to the O2 and watch the voltage. it should swing at cruising and idle, and go to rich when at WOT.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Relic1 &raquo;</TD></TR><TR><TD CLASS="quote">

If you question and seriously suspect the O2, then connect a volt meter (or A/F gauge) to the O2 and watch the voltage. it should swing LEAN at cruising and idle, and go to rich when at WOT.</TD></TR></TABLE>

you forgot "lean"

 

OK, I went to Autozone to get the OBD-II codes. And it was ALMOST the worst trip of my ITR's life.

really quickly, there is an intersection with a stoplight that intersects two busy highways by Autozone. I was about 4th in line when our light turned green. We all started to go through the intersection, and some 1000 year old lady in a big blue Buick ran her light at 55mph and almost wiped out the entire front end of #01-772. Thank god for ITR brakes. If I had been driving my civic, the crash would have been the worst ever. I was able to stop short, and swerve out of the way of the car behind me rear ending me. The old lady just flew through and kept going.

The beautiful HID JDM front end of my car almost just went bye bye. Not to mention the car itself would probably have been a total loss. Again, thank god for ITR brakes. Ok, so after changing my tighty whiteys, here is what I found out at Autozone:

they give printouts, and this is transcribed directly off of them:

P0172

The PCM has determined that during testing, the fuel system for bank 1 was too rich. (Bank 1 identifies the location of cylinder #1, while bank 2 identifies the cylinders on the opposite bank)

Definition:
Fuel trim bank one condition
Explanation:
The Powertrain control module uses the oxygen sensor to calculate the air/fuel ratio of the engine. The computer has recognized a rich or lean condition on one engine bank only.
Probable Causes:
1. - If bank 1 and 2 codes set together suspect fuel pressure of MAF Sensor
2. - Oxygen Sensor defective
3. - Ignition misfire-repair
4. - Fuel injector problem

P1457

Definition
EVAP Control System Leak Detected (Control Canister System)

Probable Causes
1. - Check Fuel Cap
2. - Failed vent or purge solenoid

OK, so that is what I came up with. Anyone got any further advice prior to the O2 sensor purchase? Also, is the factory sensor just a Bosch part? Autozone can get me a Bosch primary for $120. (not a universal one, just a straight up factory replacement not from Honda)

 

I have a o2 sensor that I could sell you for $65 shipped. If it doesn't fix your problem you can send it back to me and I will refund you the money minus shipping and paypal fees.

 

No need to spend 200 dollars on the front (primary) 02 sensor.

get the NTK sensor for ~55 bucks (part number 24172) or a Denso sensor for about 90 bucks. The NTK ones comes with the harness and connector, no splicing required.