billluch

New member - 1st post. Just bought 1989 F150 4.9L EFI w/150,000 miles. Well maintained, oil changed every 3,000 miles, great overall condition.

Truck runs great but check engine light is on. Need to resolve for a state inspection. I know Previous Owner (PO) well & vehicle history (good). Hoping to get feedback on plans to resolve check engine light.

Items of possible interest:

• Truck warms slowly, heater does not get HOT. Other threads here point to a possible "stuck" thermostat.
• Previous Owner (PO) indicated replacement of O2 Sensor temporarily solved check engine light

Plan of Action

• Go to Autozone, see if engine code provided & what it is, (?? alter plans ?? - post info here)
• Replace thermostat, spark plugs (see how they burn), PCV valve
• Make sure radiator fluid level is correct (for temperature / heat item)
• PO indicated when truck idled rough, they would soak a rag & swab intake area to resolve problem - I will do that, can't hurt (anybody have an idea on this?)
• See if there is a post back here / this forum.

My state has a 1 TIME ONLY inspection scenario. Once you pass inspection, you never have to do it again but WOW is that inspection TOUGH. I would LOVE to pass the inspection by any means possible and have time to resolve the check engine light.

I (think I) understand the PCM module and what it does so fixing this is strongly desired BUT . . . can anyone tell me how to shut off the light, what wire to disconnect if I had to?

Appreciate any feedback and suggestions on how to resolve this

NGM

You need to pull the code and find out what the code is and repair the problem. Just because the light is off does not mean the problem is gone. I don't know what they do for inspection in your state, but if its as tough as you say it is they will make sure the light works and if it dosent they might pull codes and tell you you have to fix whatever is wrong before you pass inspection anyway.

NGM

BTW Auto Zone does not have the reader for the EEC4 system that you have. You need to go to a real shop.

billluch

Argghh to your first message (and I agree).

DOUBLE Argghh to this response but I agree and thanks for the update.

You are correct about AutoZone. I called them and they said they can read 1997 and forward. BUT they told me to call Advance Auto. I did and they can do the older vehicles. Thanks for the heads up and THANKS to AutoZone for telling me about Advance Auto . . . . THANKS and take care