How many O2 sensors does a 2.3 fi 4 cyl. have........I think just one on the manifold, but I'm not completely sure......Please advise. Engine is running very rough and seems to miss at low RPMs, has no power and drinks gas like crazy!!!........Any suggestions!!.....Oh yeah, emmissions light is on on the dash.......I'm thinkin O2 sensor......tried replacing, butcouldn't get enough torque on the sensor socket wrench to loosen.....may be rusted.............HELP!!!

Thanks..................Ken - Concord, NC

 

First check the code. An '87 would have one sensor. It probably needs to be replaced, but your symptoms are not consistent with an O2 sensor.

 

Thanks for your help!!......Could it be symptomatic of a bad MAP sensor??

 

Your truck shouldn't have a MAP sensor. I am think it needs a complete tune up, look at the ignition components in particular.

 

Thanks!!!......It does have a MAP sensor, I replaced it yesterday with no change to the running condition. Can you tell me what ignition elements I might look at first......I really want this truck to run better!!...Thanks again!!.................Ken

 

The FIRST thing you need to do is pull the codes. It's simple, find the EEC test harness on the passenger inner fender by the hood hinge and put a jumper between the STI and Sig_Rtn pins. Now get in and turn the key to run and the codes will flash on the check engine light. Count and write them down on a piece of paper(you can retart the sequence as many times as you like by simply turning the key off and on again), then look up the codes or come back here for suggestions. See the links below for lots more info on doing the tests and the codes.

Ford Fuel Injection How To Run a Self-Test
Ford Fuel Injection

 

Some of the major chain auto parts stores will pull your codes for free. Just ask around.