Sooo my 98 Honda accord has these two codes P0172,P0170 which seems to indicate my 98 accord ex 4 cyl is running rich and lean at the same time? Parts I have changed are pcv valve, new battery, new cat, fuel pump, spark plugs, wires, cap, rotor, upstream O2 sensor. Basically a whole bunch of effin parts. I need to pass NJ inspections by next month and im at a lost of what to do next. MAP sensor maybe? I also don't appear to have any vaccumm leaks. Any help or suggestions are appreciated.
P0172&p0170
- Thread starter Bx6thgen
- Start date
p0170 means fuel trim issue. p0172 is rich
looks like your cars just running rich. instead of throwing parts at it try diagnosis it or taking it to a shop and actualy save money.
when you delete your codes how soon dose it pop back up ?
also do you have a scanner that shows live data or just trouble codes only ?
looks like your cars just running rich. instead of throwing parts at it try diagnosis it or taking it to a shop and actualy save money.
when you delete your codes how soon dose it pop back up ?
also do you have a scanner that shows live data or just trouble codes only ?
Rusty Accord
Well-Known Member
Looks like you need to check the fuel pressure (also look for kinks in the return fuel line to the tank, as that can cause the pressure to rise), do a voltage test on the O2 sensor using a scan tool (look for either less than .3V or more than .6v (if so, replace O2 sensor). the next step will be checking vacuum on the fuel pressure regulator to the EVAP purge valve. Does it hold vacuum? If yes, adjust clearances. If no replace the purge valve.
I hope this helps.
I hope this helps.
Get the fuel system pressure tested. Could be a weak or clogged fuel pump or injectors. If you had a vacuum leak then it would run lean and throw code P0171 which is not your case.
Both of your codes are system running rich codes.
Possible causes Faulty front heated oxygen sensor Ignition misfiring Faulty fuel injectors Exhaust gas leaks Incorrect fuel pressure.
Both of your codes are system running rich codes.
Possible causes Faulty front heated oxygen sensor Ignition misfiring Faulty fuel injectors Exhaust gas leaks Incorrect fuel pressure.
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Rusty Accord
Well-Known Member
You're thinking of the fuel tank vent valve. The purge valve is in the engine compartment. I was just going of what the FSM had for troubleshooting the Po172 code.
Well...I fixed my issue, sort of? I decided to re install my old fuel pump, just in case the old one was out putting too much or too little fuel. I unscrewed my map sensor (was pretty clean) and cleaned it up. I also changed my pcv valve and hose. The hose I was using was slightly too big. Screwing down the clamps caused the rubber to split, causing a vacuum leak. Wasn't really noticable until I changed it. Anyway after all of that I reset the ECU, and codes did not come back. Went too a NJ inspection facility yesterday and passed. I guess the moral of this story is to triple check the simple shyt first.
BTW thanks too all the members who finally responded and tried to help.
BTW thanks too all the members who finally responded and tried to help.
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