I have a 2001 accord EX V6 with 152,000 miles. It was running perfect before I removed the air intake assembly (air filter box and pipe to throttle body). I cleaned the throttle plate with throttle body cleaner and then reassembled with a new clean air filter. While I was at it I checked the PCV valve which was fine. I reassembled everything being careful to get it back together right (all vacuum hoses back correct and double checked). I may have made a mistake in not starting it immediately. When I cranked it a couple hours later it started hard and was clearly missing badly. Strangely, the TCS light was also on and continues to stay on. It is giving codes P0301, P0302, P0304,P0305, P0300 which are all for cylinder misfires. Also code P1399 which I cannot find in my manual. I'm confused because I felt nothing I did should have been detrimental. I cleared the codes by pulling the 7.5 amp fuse as the manual suggested, but the problems and codes continue to occur after clearing. Also, thinking maybe the cleaner fouled the plugs, I put new spark plugs in without any change. Any help would be appreciated! Additional note: I was concerned that the Idle Air Control sensor might have been negatively affected by the throttle body cleaner since gravity would have drained the cleaner towards it, but when I disconnect the IAC the engine RPM fluctuates indicating that the IAC is likely ok.
Hello welcome to just answer I'm Master Tech and will be able to assist you today.
so If I understand you have cleared the codes and they will come back ?
Yes, at least I cleared the codes per the Haynes manual instructions which explain to remove the desingated fuse for 10 minutes. When I restart the car the warning lights then take a minute to come up again. I do have a friend's Actron Pocketscan which I am going to try to use to clear the codes agian this afternoon. Maybe that clears them differently than removing the fuse. Again the confusing thing about all this is all I did was remove the intake and clean the throttle body in place.
right but the amount of cleaner you used will get into the combustion chambers and cause these codes.
use the scanner to clear the codes and retest. also while your in their look at the live data list and see what the MAP volts are at. make sure all the accessories off including the blower motor and the engine is fully warmed up.
I cleared the codes. The P1399 "misfire detected" code is still coming up and the engine is still running rough with obvious missfires. The scanner I have is borrowed and I am unable to read any live data as to the volts at the MAP sensor. Is the MAP sensor the most likely culprit since it is in the area heavily sprayed with the cleaner?
I cleared the codes, but the P1399 "misfire detected" code still comes up and the engine is obviously still misfiring. I can't read the MAP volts with the scanner I have. Do you think the MAP is the most likely culprit since it is in the vicinity that I sprayed with cleaner?
the p1399 is a generic misfire code that some scanners read.
it's not the map sensor that is the issue it's most likely a fouled plug. Did you remove the upper intake ?
or this has mis adjusted valves this is the reason I was asking about the live data info on the map reading.
The thing is that the motor ran perfect before I took the intake apart, so I don't think it's valve adjustment. Also, I switched the spark plugs yesterday thinking the same thing you are about fouled plugs created by too much cleaner, so they're new. The upper intake I did not remove either, just the air filter box and plastic air plenum leading to the throttle body.
Ok so all you removed was the throttle body and cleaned it correct. Did you cross the map and tps sensor plugs ?
I did not remove either of those plugs when I did the cleaning. There were vacuum lines which I removed from the plastic plenum, but those were put back as they started when I was done.
ok. well getting a true map reading on the scanner will for sure give me a idea of the issues at hand.
what spark plugs did you use ?
this motor does require a valve clearance check every 105 K like clock work. Most people don't like to do this cause is cost a lot of money but the down side is engine misfire codes just like the one's your getting right now.
I do this exact work at my dealer on a very regular basis
do you recall if this has been done yet ?
I used Autolite Platinum spark plugs bought at Autozone and checked gaps before install. The valves I beleive were checked when the timing belt was done at 106,000 miles (46,000 miles ago). It sounds like maybe the MAP could be a culprit. The valves make sense too but I'm just disturbed by the fact that everything ran perfect before I took the airbox apart. Since I have checked all the vacuum lines, could I have disturbed a wiring harness or something? Your help is appreciated!
No start with the correct spark plug their is a reason these are cheap in price. use the correct plug and then retest if you came to my dealer and I checked on the scanner for the info I'm looking for and was ok then the plugs would be the next thing to inspect. in addition these plugs DON'T need to be gapped so thats a Major RED flag for the plugs already.the factory plugs are all pre gapped and ready to install.