1991 Honda CRX CEL is on

engines
honda
lights
crx

#1

I have a 1991 Honda CRX. The cel come on when the engine gets warm after about 5-10 minutes of driving. Also after stopping and then restarting the car with a a warm engine it hesitates and stutters as you get going. This eventually goes away. My mechanic changed the air and fuel filters and the spark plugs, but he said he doesn’t have the diagnostic tools to figure out why the cel is on and why it hesitates which he thinks are probably related. The local Honda dealer also declined the opportunity to look at it because they also didn’t think they had the right tools. Any ideas? Thanks


#2

The Honda dealer is either incompetent or they may have sensed that you could not be talked into a long list of services that may aor may not help your sitiuation.

You could report this dealer to the regional zone manager of Honda, since every Honda daler has to have the proper tools to at least diagnose a…Honda!

A good mechanic with a well-equipped shop should be able to solve you problem quickly.


#3

There’s no excuse for a Honda dealer to chase you away. They should be able to diagnose and service ANY Honda.

I’m not sure you need any tools to read the codes on this car. There might be a way to jump the connectors and get the OBD to flash the codes on the instrument panel. At least that’s the way my 1991 cars worked when I owned them.

Find another mechanic. This car does not require a rocket scientist.


#4

Longtime owner of multiple CRX’s here.

Your mechanic is an idiot. You don’t need diagnostic tools to read the check engine light codes on a CRX. Start the car and wait for the check engine light to turn on. Leave the engine running (unless the light is flashing in which case, turn the engine off and then turn the key back to the ON position.

Peel back the passenger side carpet under the glovebox. You’ll see a brass-colored slab of metal where the floor slopes up. There will be a little glass peephole in it, and you will see a blinking red light when you look through it. Count the number of times it flashes in a row. Make sure to count several cycles, as if there is more than one code active, it will flash them sequentially. so, for instance, it may flash 9 times in a row, pause, flash 11 times in a row, pause, and then flash 9 times again. If it did that, you’d know that codes 9 and 11 were active.

Report back here with the codes your car gives you and I’ll help you further.


#5

It flashes once then goes off for 4-5 seconds. So I think the code is 1.


#6

That’s the code for the oxygen sensor circuit. It means a bad or unplugged sensor or a bad circuit (broken wire).

The oxygen sensor is located on the exhaust header. It looks sort of like a spark plug. Make sure you verify that it’s bad before you replace it, because it’s a $150 part. To test it disconnect the wire from the oxygen sensor. Then start the car, warm it up until the radiator fan turns on once, and then measure the voltage between the connector terminal and a ground while a friend revs the engine by pressing the throttle all the way to the floor and then letting up after it gets above 5,000 RPM. The voltage needs to be above 0.6volts when the throttle is floored, and below 0.4volts when your friend lifts up on the throttle. If it is, then you know you’re getting proper power and therefore your oxygen sensor is bad. If it is not, then you probably have a break in the wire somewhere, although in rare cases it could also be a failed ECU.


#7

Thanks. I’ll work on the O2 sensor.