Truck won't give Check engine light codes

So I have a 93 mazda b2200 Fuel injected. I know on the carb units the check engine light indicates EGR problem. There are no EGR on fuel injected b2200's. I know this because I went and bought one from Mazda for over $300 bucks and couldn't figure out where it went and finally took it to my trusty mechanic and he said only the carb units have EGR's. Explains why I couldn't find it. So I returned the EGR.

My check engine light is on and I have tried a couple different ways to check it out one of them being on this page. This is my setup.


I can't seem to get it to work. Nothing blinks The test light and check engine light just stay solid When I turn the ignition on. I'm Thinking its The o2 sensor because it burns rich and doesn't have the power it should have. Acceleration sucks. Gas mileage sucks compared to what people claim to get with these trucks. Plus the o2 sensor looks like its really old and was never changed. Could possibly be a problem with the ECU I'm thinking. I've read on these forums of similar problems with lacking fuel mileage and power/ burning rich due to ECU's leaking fluid and maybe this is why I can't get my ECU to display the morse code to tell me what's wrong.

What Ive done to my truck is the following,
New cooling system from temp sending unit to radiator to water pump. Culprit was actually the water pump and clogged heater core.
NGK Wires plugs and new rotor and cap.
New rocker arm cover gasket
New timing belt Kit
New air Filter
New suspension parts

Want to exhaust all my options before I take it to my mechanic and before I buy and replace the o2 sensor myself. Maybe I am doing something wrong why I can't get the check engine codes to work. Anyone have any ideas??

Check engine light is for the timing belt, should come on every 60K miles (965 60.64km). To reset it look here.

post76513

Welcome to the forum!

Sorry I forgot to mention I've already done that as it was said in other threads and forums.

I have never had any reason to check for codes on my truck as the check engine light has never illuminated. Do you have a haynes manual or service manual? I have almost every sensor on an EFI B2200 as spares, including an ECU, if you suspect a sensor issue, I could possibly sell you a sensor to test, and if it does not fix, you can return it. I know looking on Rock Auto, just about every sensor or electrical item on these trucks are $200 and up.

Is your truck US Federal, California, or CA emission?

And you had the single green test connecter properly grounded when you were trying to pull codes?

If that o2 sensor looks so bad, I would change it anyway - whether it is the cause of your light or not.

I would also open up the ECM and look for signs of cap leakage. There are plenty of threads with pictures that will show you what to look for.

You know I am not sure what the emissions are. How do you find that out? I am pretty sure I had the green connector grounded properly.

Yes I have a Haynes manual. I just came back from farm today and started the truck up and the light is off now. Right before I posted this thread I switched the connectors under the dash and it went out then came back on and is now off again so I'll see if it comes back on again.

I'm thinking of just switching o2 sensor anyways I can get a NGK one off ebay for 45 bucks. vs 75-115 buying at canadian tire. Ill look into how to check ECU Be good thing to know either way. Thanks

O2 sensors get sluggish with time. But have you given any thought to doing a fuel system service. It's more likely the fuel injectors have gotten deposits on them and that would cause some of what you are talking abut inside your thread.

I have thought about changing the fuel injectors but they are so expensive and Don't want to drop that kind of money on them. I was thinking I might take them out and clean them when I have time. They do kind of have a sooty substance around them.I did change the fuel filter awhile back.

I work out of town for two weeks at a time and am going back tomorrow so when I get back from work I am going to start to do some of this stuff.

There is a place on the south side tested mine snd rebuilt 2 of them, pretty cheap too, like $80 for all.

Thats not bad. I was checking out canadian tire and ebay and what not for injectors and they're over 100 bucks for a new one. What is the name of the place?