I have 4 im monitors that dont seem to want to reset on my 1999 honda ex 1.6 4cyl engine. i had a problem with the O2 sensor and i replaced both with an OEM part from auto zone, the service engine light did go out i did reset the codes with my OBD meter and drove the car a good 400 miles but when i check it again with the meter 4 im minitors still shows inc. oxygen sens.(inc) catalyst mon.(inc)oxygen HTR (inc) EVAP system mon.(inc) any suggestions. thamnks maynard

SOURCE: code PO131

Code PO131 is O2 sensor circuit low voltage , bank 1, sensor 1. That sensor I would say is the one in the exhaust manifold. I would check voltage to the sensor from the computer. If the voltage is not 5 volts, then it could be a computer problem or a wiring problem. I have seen factory wiring and connectors give a voltage problem. Check for a damaged or burnt, pinched wire. You need to know for sure that the voltage is correct to the sensor. Intermittent problems are hard to trace , but patience and knowledge helps.

sheiden9

• 87 Answers
• Posted on Apr 05, 2009

SOURCE: 1998 honda accord obd code P0171 and P0170.

Hi,welcome to fix ya.
p0171 is for a lean fuel condition .A variety of things can cause this code the most common one is a bad o2 sensor but a plugged injector,fuel filter or dirty egr system can cause this as well.

SOURCE: Check engine light

Sometimes can be prematurely dirty air filter, sets off the air flow sensor, which sets off the o2 sensor. So might try new air filter first and erase codes and then see, before you spend more bucks than you need; then if codes return, do the flow mix sensor.

SOURCE: Check engine light was on.

If the check engine light stayed off then that means that those errors are not present at this time. It is not un common to have intermittent faults but I would not preced any further until the light comes back on. Then re-scan the code see which are to begin diagnostics.

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