whatyoutalknaboutwillis

Long time lingerer here with a quick question. I have a 95 cab with a check engine light at start up that goes away once the car is driven. It will appear again at idle and fade away with use and pops back up every now and again. All the fluids are up to snuff and the belts look good--gas cap is tight. I am at 85K and will probably do the 90K service soon. I don't have a OBD 1 reader but being in So. Cal I bet I can get a half dozen at the next PCA breakfast. Anything I could look for in the meantime? Thanks in advance--nothing in the search function.

stace

not unusual. mine did exactly that until I changed the O2 sensor. one for 95s and an easy DIY.

Nuff

I learned here that in the MY95s, you can check the CEL codes without an OBD reader. If you turn the ignition on and hold the gas pedal to the floor for three seconds (and don't turn the car on) and wait for the CEL to flash and then take your foot off the gas you can read out the fault codes. The CEL will flash out fault codes almost like morse code. If there are no faults the CEL will flash once then pause and then flash 5 more times.

You should have a single flash then a pause, then a single or a double flash. If the flash is double then the fault is intermittent (loose contact) otherwise the fault is constant. And then the following flashes;

11 Supply voltage
14 Engine temp sensor 2
15 Throttle potentiometer
18 Rpm signal
19 Speed signal <- Speedometer
21 Hot Film Mass Air flow sensor
22 Oxygen Sensor (Signal)
23 Oxygen regulation
24 Oxygen sensor
25 Intake Temperature Sensor
26 Ignition timing change
27 Opening winding of idle stabilizer
28 Closing winding of idle stabilizer
31 Knock sensor 1
32 Knock sensor 2
33 Control unit faulty
34 Hall signal
36 Idle CO potentiometer
41 Control unit faulty
42 Fuel pump relay (DME-relay)
43 Tank ventilation relay
44 Air Pump
45 Check Engine warning lamp
51 Injection valve cylinder 1
52 Injection valve cylinder 6
53 Injection valve cylinder 2
54 Injection valve cylinder 4
55 Injection valve cylinder 3
56 Injection valve cylinder 5
67 Ground and plug connections
69 Ground and plug connections

Stace is right. It's probably an 02 sensor. My 95 was doing the exact same thing. Got mine from Pelican (993-606-126-01-M14 ) for $103.75. Took about 20 minutes to swap.

jimbo3

Or, you can go to just about any auto parts chain store and they'll read the code for free.

kkim

Do they read OBD1 codes? I assumed they only did OBD2.

Nuff

My local auto part store doesn't read OBD1 with the round plug. Not sure if they would read it if it had the newer port.

whatyoutalknaboutwillis

Thanks for the replies. Time to tinker.

Marlon

I had the same thing at 60K miles recently: O2 sensor.