Hi all: I have a 2007 Pilot and have been suffering of power loss about 4 weeks ago. It will not run over 40 or 50 km/h in a not so bad incline. It kind of runs OK on horizontal and of course, going down hill. Already replaced spark-plugs, oxygen sensors and injectors. It seems more powerfull when cold. Also, I checked compression, one cylinder (middle, front) is low (just below Green) others are OK. Pressure from fuel pump is OK.
Thanks for your feedback
Is the check engine light on, and/or "D" light flashing? Certain DTCs will make it barely run in a default mode.
Did you check the quality of fuel while doing the pressure test (water, diesel, E85)? Also, fuel pressure good at idle or not running does not necessarily mean it's still good under a load while you're losing power.
Does it run smooth or rough?
Other than that I would be looking for a clogged cat (or air intake), and cam timing being correct.
Hi Admin: While pressing the pedal almost to the bottom going up hill there were flashes of the mil light, also, the vtm4 light lit up and stayed on until turning off the engine and restarting.
Yes, it runs a Little rough if I try to go over 3000 rpm. Below, is fine. When I accelerate, the rpms go to 4000 rpm but there will be no shift until I ease the pedal and try to again accelerate at a moderate rate.
The engine seems ok when starting it from cold, but it will not rev past 4000 rpm. I can take step hills when cold at low rpms (below 3000) and after driving for half an hour, the vehicle will almost halt to the same hill.
No I did an stopped engine fuel test, not running. Did not check for fuel quality. Another thing is that fuel consumption increased (Last Friday to Monday, one full tank (60 l) and did not use the car a lot.
No MIL light on right now. Some days ago received a "excesive flow EGR valve" when pressing the pedal hard (goes to 4000, then revs down to 3000 and if continued it will stall completely unless the pedal is released)
Thanks for your advice
The check engine light flashing means the PCM sees a major obstacle in emissions, typically a misfire. But the fact it runs fine at low RPM leans me towards an obstruction. And the previous low EGR flow DTC points towards exhaust.
How many miles?
Have you checked for DTCs since the light was flashing? Including temporary DTCs,
I would check for an exhaust restriction (usually the rear cat comes apart at high miles). Remove the rear upper 02 sensor, shield the firewall and hood insulation with tinfoil or something, and take it for a ride. Tell me if power comes back with O2 out. If not, repeat test on front cat.
Another way to inspect the cats is by dropping the engine pipe, and looking up inside both. If one came apart, you'll see it. Should be a clear honeycomb pattern.
Hi Admin: 167,000 miles, however, half engine replaced about 80,000 miles ago, also replaced both catalytic converters and the one below.
No DTC codes, permanent or temporary.
Will do what you suggest, looking into the cats (with a boroscope)
Thanks, will keep you informed
You replaced front and rear cats how many miles ago? And were they Honda or aftermarket? Aftermarket cats are junk.
You can pull the top O2 sensors and look inside with a borescope, but the images are often not so great. I prefer pulling the O2 and road test, or drop the engine (crossover) pipe and look from underneath -- two minutes on a lift, not so fun on your back.
This is a process of elimination. Best bet right now is conclusively condemning or excluding an exhaust restriction as the problem.
Hi Admin: You were right. It was neither of the cats on the engine, but the one beneath the floor. Now I recall that I only changed the ones in the engine I did what you suggested, taking the pipe down and looking up into the cats. You are right, borescope images did not show much.
After taking the floor cat out, I took the catalyser out and now the vehicle is running OK. Already bought a new cat from Autozone, however, it will be the original Honda replacement. It will be here in a week or so (imported from the USA)
Thank you very much for your insight and help.
About 40 years ago I had a similar problem with a two stroke motorcycle. Exhaust pipes were filled with burned oil and carbon.
Best regards to all