OK, my son has a 94 Ranger with 4.0L, manual trans. Engine light bulb was burned out so we replaced it, noticed the CEL immediately came on and stayed on while running. The engine runs rough and is getting terrible mileage.

Using a digital code reader for the KOEO test, this is what I got.

111
172
173
176
177
214
332
337

Whoa, thats a lot of codes but I think some are all related to each other. Can you guys throw me some tips on what to check first without spending a bunch of money on parts I don't need?

Thanks,
Rich

 

I'd start with the 214 code, since it could be the cause of all those conflicted 02 sensor codes (172,173,175,176). The EGR-related codes (332, 337) can wait, as well.

Continuous Memory DTC 214 indicates an error has been detected in the Cylinder Identification (CID) input signal. The error could be due to a hard fault or an intermittent condition.

Possible causes:

-- Open or shorted harness.

-- Damaged Camshaft Position Sensor (CMP).

-- Damaged Powertrain Control Module (PCM).


I think it's fair to assume that your son's Ranger is a California model, meaning it has sequential electronic fuel injection (SEFI) which necessitates the use of a CMP sensor (the other 49-State, 1994 4.0L Ranger models use batch-fired injection, and so there is no need for a CMP sensor).

The CMP sensor on a Ford 4.0L OHV engine is, unfortunately, not the easiest thing in the world to access. Its located on the top center of the engine, toward the rear (i.e., closer to the fire wall). It's kind of buried under the upper intake and other stuff.

 

well last night I went and disconnected the connector to the MAF and the engine ran smooth as a watch (wtf?) which I've read means the MAF could be dirty or faulty, so I removed it and cleaned it well with some MAF cleaner and compressed air. Replaced the MAF, plugged in the connector and started it up and it still runs smooth as a watch. I had kid run it around the block several times and when he came back it was still running smooth as a watch, so I am gonna clear the codes tonight and drive it around to see if all the 17X codes go away. I also checked all the vacuum lines to the EGR, etc., all of which are good, tight and not cracked. Another one code I forgot to mentioned is 211.