Hello, I am new to this board but going on almost 3 years with my Subaru. I have a 2002 OBW 5MT. 75K miles. Did 60K myself. I just replaced the spark plug wires with OEM because the first set I had were not. Plugs are NGK. Getting missfire codes on all 4 cylinders. PO301-PO304. I replaced the fuel filter (OEM). The problem seemed to go away after putting in the OEM wires but came back the next day. I tested my TPS and came up with this: I tested the input and signal wires going to the TPS. Input was 5.14 v. Idle was .42 volts WOT was 4.23. I played with the TPS adjustment and got the idle to .5 but it then idled at almost 3k RPM. Testing the battery gave me 12.02 volts. My multi meter was grounded to the negative on the battery. I just tried to adjust the TPS so WOT is 5 volts but the most I could get was 4.7. with the TPS fully adjusted, idle is at 1.02 volts. I got the codes read again tonight and found these extra: P0122 Throttle Position Sensor Circuit Range Problem P0123 Throttle Position Sensor Circuit High Input P0172 Fuel trim malfunction (A/F too rich) (came back right away after clearing the codes) P1137 Front oxygen (A/F) sensor circuit range/performance problem the 122 and 123 codes are probably from the time I tried to adjust my TPS for the higher WOT voltage, it was idling at almost 3k with the idle voltage at just over 1 volt. I don't like to drive it because some times it will not go unless I am at WOT and then, well, I am going at WOT and my fuel economy is terrible and not to mention hard on my clutch. I want to test the coil, but I have heard mixed results on the testing results. I will try that tomorrow night. Dealer's won't let me return a coil if it does not fix the problem so I don't want to put the cash down for one if it is not the problem. Any other ideas? right now I am just thinking it could be the TPS or my coil. I would love to go to a meet some time, so I'll keep my eyes out. Someone should have a car worth chuckling at, and an OBW surrounded by STIs (and not even a sleeper OBW). Plus, who wants to see what baseball size hail can do to an OB body?
Yep, that was it. I checked the online places for the front O2 and found OEM running around 100+ including shipping. I picked up a front O2 sensor from Bloomington Acura and Subaru for $92. It took me longer than it should have- 1.5 hours but I checked all the connectors, checked for vacuum leaks and swapped out the front sensor. I don't remember the car running this well. We'll see how it drives tomorrow. Thanks for the encouragement and hopefully I will see you guys soon! Anyone live near Chanhassen? I have a bouldering cave in my garage and people are always welcome to stop out and climb a little while people work on cars- I just need a heater for my garage...
not to brag- it has been a lot of work, but it is a ton of fun. This picture is not quite up to date and I have more holds up now. It spans over both cars in the garage
