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Any weight to the premise that if you replace one, you replace 2, or for that matter all 4?
No. Just replace as needed.
 

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Check the fuel trims on banks 1 and 2 after the engine is at operating temp. They should be about +/- 10% or less. If the fuel trims are pegged high + you have a vacuum leak and the PCM can’t add enough fuel to compensate for the leak. A vacuum leak means any air entering the engine downstream of the MAF so check the intake hose for a leak. Since you mentioned an evap system failure, double check to make sure you reconnected any vacuum hoses disconnected, especially the vacuum hose to the evap purge valve. Sensor 1 is used by the PCM to regulate the air/ fuel ratio. Sensor 2 is used to monitor the catalytic converter performance. If the fuel trims are normal then most likely there’s a faulty sensor 2 or wiring problem in the circuit.
 

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Discussion Starter · #23 ·
Check the fuel trims on banks 1 and 2 after the engine is at operating temp. They should be about +/- 10% or less. If the fuel trims are pegged high + you have a vacuum leak and the PCM can’t add enough fuel to compensate for the leak. A vacuum leak means any air entering the engine downstream of the MAF so check the intake hose for a leak. Since you mentioned an evap system failure, double check to make sure you reconnected any vacuum hoses disconnected, especially the vacuum hose to the evap purge valve. Sensor 1 is used by the PCM to regulate the air/ fuel ratio. Sensor 2 is used to monitor the catalytic converter performance. If the fuel trims are normal then most likely there’s a faulty sensor 2 or wiring problem in the circuit.
Great info. I will check my obd, and look it over. I did yesterday but it was hot. So I didn't reach in to much. I also plan to check the o2 sensor today.
 

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As with others comments, you're a shooting in the dark until you can see data;

is the live data output from this sensor pegged lean with no response to throttle blips?
Compare the live data to Bank 1 Senor 2, for reference behavior.

I suspect Bank1 Sensor 1 is active and fuel trims are near nominal.

Probably not MAF or MAP related.

The key may be spilled trans fluid on 02 sensor; if it migrated into the ambient-air passages and into the sensor element, contaminating it, probably not salvageable/cleanable. If the trans fluid contaminated the connector, pull it apart, clean with brake fluid and re-assemble.
 

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Discussion Starter · #25 ·
As my pipes and engine cool, I took the front wheels off and pulled the front brakes apart. When last I checked the eye test was I couldn't see anything wrong. This time I pulled the calipers and greased the back of the pads and took pins out and greased. Put it all back. When all cool, I will pull sensor and unplug. Clean and see what I see. After I put it back, I will run the car and see if I can find the data.
 

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Discussion Starter · #26 ·
Ok, the sensor is welded to the exaust. I will work on that at another time, maybe after I submerge it in lubricating oil.
For the record I am using car scanner pro and a kobra elm 327. Normally just scan codes, so I am not 100% sure what I am looking for, but this is what I found.
At idle when warm, I clicked live data, combined, and looked at ( all are bank 1 and 2)short term fuel trim , o2 sensor voltage and o2 sensor fuel. I will post screen caps, but at idle and mostly the is a big difference between 1 and 2. When I Rev they seem to normalize mostly but the. Slip back to a difference. Now I am not sure on some of these because they are -. I mean to say, if we are I the negative I don't know which one is more or less. Ty again and here are the caps.
Rectangle Font Slope Parallel Pattern
Rectangle Font Slope Parallel Pattern
 

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The takeaway is that both banks are in closed loop control via the upstream sensors , and therefore the pegged lean Bank 2 Senor 2 is likely an issue directly with that sensor; wiring, connector, contamination, bad exhaust gasket letting air into exhaust pipe.
 

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Discussion Starter · #28 ·
The takeaway is that both banks are in closed loop control via the upstream sensors , and therefore the pegged lean Bank 2 Senor 2 is likely an issue directly with that sensor; wiring, connector, contamination, bad exhaust gasket letting air into exhaust pipe.
I will eat my spinach and muscle up. Does the plug hook up to the same spot that the bank 2 sensor 1 does? Right next to the pcv?
 

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Discussion Starter · #29 ·
Is this a mission critical fix? Seems to be driving fine. I am going to pull it off and look at both ends, but if I leave it does it ruin something else of can I wait a few weeks.
 

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Discussion Starter · #30 ·
So I pulled it all apart, both side of the plugs and boy were they gooped. I either made it better or made it worst. It's all clean now, but in pulling both apart, I hope I didn't fowl the other sensor.

I left the plugs unconnected to dry out until tomorrow. I used degreaser first on the wires, and the maf cleaner inside. All looks clean. Hope for the best. I guess I could have spilled the atfluid in other bad areas, but maybe this is an argument for fill port over dipstick. Either way, I would have made the same mistake with the funnel.
 

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So I pulled it all apart, both side of the plugs and boy were they gooped. I either made it better or made it worst. It's all clean now, but in pulling both apart, I hope I didn't fowl the other sensor.

I left the plugs unconnected to dry out until tomorrow. I used degreaser first on the wires, and the maf cleaner inside. All looks clean. Hope for the best. I guess I could have spilled the atfluid in other bad areas, but maybe this is an argument for fill port over dipstick. Either way, I would have made the same mistake with the funnel.
If you have dielectric grease, consider putting some on the electrical contacts.
 

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Discussion Starter · #32 ·
If you have dielectric grease, consider putting some on the electrical contacts.
I do, it's all I had to put on the gas cap. So far no check ur cap messages now that I think of it.
 

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My guess goes to valves adjusted too tight.
 

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Discussion Starter · #34 ·
My guess goes to valves adjusted too tight.
At this point I know the o2 sensor isn't working. My clean up didn't work. In rerunning my scanner I found p0157, I think, which shows the low voltage on the 2 2 o2. Either way, I think the first step is a new sensor, and I will chase it down from there. I also ordered the ac actuator and a new pcv. Next would be the evap if the check cap comes back. I am sure there will be nothing from there.
 

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I think that it's too big a coincidence. "Low sensor voltage" is a sign of a lean mixture, beyond what the PCM is willing to trim to. The oxygen sensor is used to read CO upstream of the catalyst. CO proportion is a pretty direct indicator of fuel/air ration during combustion. Low readings indicate low fuel to air, or too much air for the fuel. A tight intake valve will do that, as will a vacuum leak. So I'd be looking hard at the work done in that area as part of your projects. Start with the easy stuff like dislodged or missing vacuum hose, and dig deeper from there towards the valves.
 

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Discussion Starter · #36 ·
Other then pulling the intake off, I checked all items I did or undid during the valve adjustment. Now I know significantly less then just about anyone on the forum. This is mostly all new to me. The last engine I did significant work on was my 84 and 89 mustang. Which I haven't owned in 25 - 30 + years. However I am more familiar with what I did. Which in my case is mess things up. But if anything I would have left things looser. When I commented about not being sure I was successful, but I was consistent in whatever mistakes I made. I also have questioned my work in an ocd type questioning. Meaning all of that goes thru my mind, what did I do wrong, did I forget to tighten something. Normally I am pretty consistent in checking if it's tight. Like I listed I broke the cover pin, because I was doubling back to make sure it wS tightened and it popped.

The easier this to do at this point is replace the o2 and like I said I also got the pcv. Oh and I can sit in comfort as well, when I get the ac part. Less sweating during my panic.

If the results don't change after the o2, I will pull the bank 2 valve cover off and recheck the valves. I don't get the parts until 9-22.
 

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Discussion Starter · #37 ·
So 2 things, first after cleaning everything last night, greasing and putting the connectors this morning when I got in the car I didn't reset the cel before driving. I tried while driving but I don't think that's suppose to work like that, or it's never worked for me. When I got home, I shut the car off, and put it into the on setting and cleared the code. In the previous 2x I cleared the code it cam back roughly 5 minutes into the next drive. This time I wasn't thinking about it but I got to my daughter school, about 20 minutes away and no cel. I will connect it for the drive home and see if the live data is different.

The second thing, I am sure makes more sense to someone else, if the valves require such a precise setting so much so, that the slightest discrepancy makes them to loose or to tight, why give a range of sizes to use? Why say ( I don't remember the ranges) .20 to .24 and .28 to .32 ( I used .22 and .30 I believe) ? I understand that in reality a range is within the window of effectiveness, but why not be more specific? If .20-.24 is the range, then use the .22 precisely half way. So if my loose is another person's tight, it's still good, but if I use a .22 and error on the side of loose maybe I am over the .24. I have gapped many spark plugs in my early days. I also used ( I can't remember the name but I the pincher thing that measures down to a Chinny chin chin ) my father had the old school one and later I used digital. If it said the gap was 12345, I made it 12345. I have watched probably 10 videos online of the lashings in these engines. Each one told a similar story about roughly how the feel of it goes. However it was not a general consensus as to whether to error on the side of tight or loose. Several had there own theory as to why doing it one was was better then the other.
I am an able-bodied person. Can handle most diy situations with some guidance. Usually if I have done it once I am good. Better after that. I also know I am not an expert and will always look for who or how to do it better. I know others have commented but a special ty to nail and the doc. And others.
 

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Discussion Starter · #38 ·
I think I will just pull the cover and check the valves. I got time before the parts arrive. It will let me double check all I did and undid, it will eliminate that being the a problem and it doesn't cost anything. At least it's not the rear bank. Thanks again Dr. Bob we will see if this is the issue. I didn't touch the fuel stuff other then maybe leaning on it while working. Any chance its a fuel issue? Does lean mean less fuel like a clog. I have put Seaform and Lucas in the fuel.
 
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