Check Engine Light, and Whole Bunch of OBDII Codes

[soxfan50]

So I took my 2002 Accord EX V6 3.0L Coupe, Automatic Transmission (66,600 miles) off the road back in early 2013, for various reasons, mostly because I was using public transit for work.

I finally got it back on the road a couple weeks ago - siphoned the old gas out through the fuel pump access panel in the trunk (there was over 1/2 tank of 2+ year old gas in there), changed oil, coolant, power steering fluid. I've also changed the transmission fluid, as that was due about the time I took the car off the road - I had been experiencing shifting issues, especially in the cold, and these seem to have improved a little (but not much). But that's another story.

The vehicle seems to be idling rough at times, and a couple times on a cold start, there seemed to be a bit of a sputtering sound coming from the exhaust area (this seemed to clear up as the car warmed up). After hitting a few drive cycles, the check engine light came on, and I had AutoZone run a code check, which read the following (this was a single line reader):

P0131
CATALYST EVAP
O2 SNSR
HEATER
EGR
5 READY
MISFIRE
FUEL
COMP
O2 SENSOR
O2 HTR

I may just end up bringing it down to my mechanic, but with my work schedule, even that's difficult. Was hoping people here might have some input on what issue(s) could be causing these codes. Various research has indicated changing the spark plugs/O2 sensors could be a relatively easy/cheap fix that I could do myself, but also may not take care of it.

Thanks in advance for any help.

 

[james'99]

It only seems like you have one code, no? P0131. I would honestly continue driving it for a little bit to let the sensor heat up and burn off anything that is on it, then unplug the battery for a while and see if the code comes back.

Did they give you a print out?

 

[soxfan50]

No print out, unfortunately - I just threw what the OBDII device was reading into a draft text message while the AutoZone employee scrolled through. If the non-code phrases (CATALYST, EVAP, etc.) coming through the scanner weren't problem codes, what were they? MISFIRE sounds especially troubling, but I'll admit, I'm pretty new to doing repairs/maintenance on this vehicle (or any, really) on my own, so definitely still learning.

Based on the physical issues (rough idle, sputtering exhaust noise), as well as some issues I'm recalling dealing with in late 2012/early 2013, prior to taking the car off the road (poor fuel economy, failing an emissions inspection at one point that was remedied only by resetting the CEL and getting the car reinspected before a drive cycle completed), I'm leaning towards it being an actual issue. I've also driven the car about 200 miles since I brought it back on the road (and the CEL just returned towards the end of those 200).

I have been doing research on my own since my initial post, and at the very least, it looks like P0131 is "Primary Heated Oxygen Sensor (Primary H02S) (Sensor 1) Circuit Low Voltage." Changing out the O2 sensors doesn't seem too difficult, and I found some Denso sensors on Amazon.com - $43 for the primary, $23 for the secondary, so I may even just do both (free shipping on orders >$35, so I wouldn't qualify if I had to/wanted to purchase the secondary sensor separately later on).

It also seems like cleaning out the EGR valve/EGR ports with some carb cleaner and maybe a vacuum wouldn't be TOO difficult, especially the valve (the ports seem a little more involved in accessing). If I can do all these, though, it seems like it should (hopefully) knock out most of those codes, I think?

This still does leave CATALYST, EVAP, 5 READY, MISFIRE, FUEL, COMP as mystery readings (and, as I mentioned, MISFIRE sounds worrisome, especially given that some of my research has indicated that continued driving on a misfire could render the catalytic converter useless and in need of replacing). I'm kind of hoping that an O2/EGR clean up will maybe clean up some of those other codes, as well. There's also the spark plug replacement (and maybe coils?) that I believe I saw as a potential fix for misfiring.

I'm going to continue researching, and I'm happy to keep this thread updated (both for my own record, and others to refer to), but would obviously welcome any and all thoughts/input/suggestions!

 

[james'99]

I don't have too much time right now but I think you only have one code. The rest explains the status of the monitors.

See how they say OK next to them? In your case, that is what the 5 ready means.

I think all this...

CATALYST EVAP
O2 SNSR
HEATER
EGR

is telling you the monitors that weren't ready as yet. Definitely replace the O2 sensors. Let me provide links to alleviate confusion as I once made the mistake of ordering O2 sensors that were universal...

http://www.amazon.com/Denso-234-4727-Oxygen-Sensor/dp/B000C5YD1U

http://www.amazon.com/Denso-234-4621-Oxygen-Sensor/dp/B000C5YCUM

So it looks like you had the correct links.

Let me know if you need further explanation!

 

[soxfan50]

This is very helpful, thanks! The OBD scanner AutoZone used had a much smaller display screen, and literally only displayed what I listed below (and pretty much one word at a time). I didn't see any indication that these were "OK," but I suppose that could have been because it was just a cheap scanner (or maybe I missed it). Either way, what you're saying definitely makes sense.

I ordered the O2 sensors this morning, actually prior to reading your reply. The Denso website (densoautoparts.com) allowed me to enter the year/make/model/trim to narrow down the exact part nos. needed, which matched what you provided.

I'll change those out, reset the CEL, and report back. Thanks again.

 

[james'99]

This is very helpful, thanks! The OBD scanner AutoZone used had a much smaller display screen, and literally only displayed what I listed below (and pretty much one word at a time). I didn't see any indication that these were "OK," but I suppose that could have been because it was just a cheap scanner (or maybe I missed it). Either way, what you're saying definitely makes sense.

I ordered the O2 sensors this morning, actually prior to reading your reply. The Denso website (densoautoparts.com) allowed me to enter the year/make/model/trim to narrow down the exact part nos. needed, which matched what you provided.

I'll change those out, reset the CEL, and report back. Thanks again.

In this case, ready would be equivalent to the OK. That's where I was going with that. And yeah, that's exactly where I got those P/Ns from! But did you see the one that said universal? I made the mistake of ordering that one and ended up returning it. Happy to help!

 

[soxfan50]

In this case, ready would be equivalent to the OK. That's where I was going with that. And yeah, that's exactly where I got those P/Ns from! But did you see the one that said universal? I made the mistake of ordering that one and ended up returning it. Happy to help!

I did see the universal ones - after reading (I believe somewhere on this forum) that the OEM sensors are Denso anyways, and I had already located a few on Amazon before going to the Denso site to be sure I had the right part nos., so I was already comfortable with the price of the OE's.

 

[james'99]

Awesome! Keep us posted buddy!

 

[soxfan50]

So, you were right. I switched out the primary O2 sensor, and as soon as I started the car back up, the CEL turned off. So that takes care of that.

The secondary O2 sensor is stuck pretty good, however, and I may need to grab a breaker bar to get it off. Since it wasn't causing the primary problem, and the CEL went off, I'm not in a huge rush, my try to get around to it this weekend.

I also tried to clean out the EGR and IACV, but ran into a little trouble there, as well - the throttle body was stuck pretty good (and I didn't have anything like a wood block or rubber mallet handy to try and break and loose without causing actual damage) and the nuts on the EGR were in pretty good (need to pick up/borrow some joint sockets, I think). My fuel economy still isn't great - took the car out for a day trip after putting the new primary O2 in, about 180 miles round trip, and burned through nearly half a tank. I'm still also dealing with some minor rough idling, and the exhaust still has a sputter to it when the car starts up but hasn't yet been drive. Hopefully it's those issues.

Either way, thanks for the help! Having a clear dash certainly is nice!

 

[james'99]

Glad its better! Dump a can of seafoam in the tank at your next fill up. Walmart has it cheapest. Obviously the fact that the car sat for two years is important in this case. Check your air filter and all the obvious. It will get better. Just need to get it all the way there.