[r7k]

it's my nephews truck. he was periodically getting misfire codes over the winter, and had also gotten some bank rich codes, happened on either bank. Pretty sure he never got any lean codes.
I would check the truck with my innova handheld around once a month when i saw him and there were always stored codes for misfires, but he said the truck ran great nothing noticeable other than check engine light. I know nothing about honda, figured the egr was likely a problem going off youtube showing how the egr port gets clogged. EGR on any vehicle after 100k miles tends to become a problem one way or another.

But maybe that specific intake manifold that is prone to egr clogging as shown on youtube is only on cars and not the ridgeline, or the 2007 or whatever year ridgeline started getting this updated intake manifold? there's no way this egr on this manifold is clogging, and as far as i know this was the original oem manifold. so if anyone wants the egr kit F23001 and B22001 email me, we got it from rockauto not worth returning it.

That evening I came across mentioning of valve lash adjustment, and how loss of lash on exhaust valve would cause leakage around that valve causing the O2 sensor to read rich and set the corresponding DTC for a rich condition. That made the most sense, ended up re-pulling intake next morning and valve covers, pretty much all exhaust valves were tight could not wiggle. The few intakes i checked all had some wiggle. Adjusted all intakes to 0.009" and all exhaust to 0.012". Truck hasn't been driven enough yet to know but it runs great for the 10 miles i drove it afterward, engine is quiet on startup, so I'm fairly confident that was the solution. Everything on truck is stock. Timing belt I was told was done. There were denso IK16L iridium spark plugs in it, and all spark plugs looked perfect and clean, no sign of ever running rich or burning oil.

if anyone is looking to do a lash adjustment, i can say it's not horribly miserable. the front side is easy. got the typical scraped fore arms from plastic and metal stuff around engine.
with plugs out i was able to spin engine over via pwr steering pump pulley 19mm bolt and adjusted valves based on exhaust opening intake closing, that made it easy. i was not able to see the number in the inspection hole thing seemed like a waste of time since you can see everything anyway. worst part was doing aft head and laying over engine, can't see them so gotta go by feel to get feeler gauge positioned between rocker and valve tip then turn the adjuster and tighten it while laying over engine.

had also installed two new front O2 sensors, and already bought a new EGR valve from autozone. the EGR on it had a siemens sticker don't know if that was original or had been replaced. And cleaned the carbon out of the throttle body. this ridgeline has 165k miles on it. I don't plan on signing back into this forum unless the check engine light comes back and my lash adjustment was not the solution.