Had the Check Engine light on my '97 Ranger (4 cyl) checked yesterday, and the code came back as "System Too Lean". They didn't have any ideas on what this could be. How 'bout you guys?

 

what where the codes exactly? It could be your O2 sensors! , where did you take it, that they don't kkkow what the codes mean?

 

I just took this down to Autozone (probably my first mistake). Didn't actually see the codes, but he did show me the "system too lean" message. He said that doesn't tell him anything, that he couldn't tell if it was the 02 sensors or not. He reset the thing, and it hasn't come back yet.

 

or it could be a vacuum leak ....you need the codes to know what direction to go in

 

if i were you i would buy a code reader! they run from the $40 range and up, the simple should do to read the code and erase it.

 

O2 is good bet, to T/S you need to see sensor outputs (volts, pressure, ohms, info., etc.)

 

erasing is the easy part you dont need anything put to dissconnect the battery but if you dont fix the problem it will only return

 

Hey I am new to the forum but I had a similar problem with my 97 4.0. Autozone also told me that the system was running to lean and the local ford dealer told me I had a blown headgasket. It ended up being the o2 sensors. I replaced all 3 and put all new spark plugs in and it solved the problem and it now runs great with 133000 miles on it

 

Had this problem with mine. Turned out the PCV assembly was rotted and leaking. Replaced it all codes gone. Same as a vacuum leak i guess.

 

A lean running system is not always the air induction as being a culprit. A great amount of time it is the problem,weather it being a bad 02 sensor, malfunctioning, or even not correctly placed. But with that being a problem it could also be fuel amounts running also as with lower amounts of fuel it may read as a lean system as it did for mine just with a normal code reader. as your vehicle goes on not many people think of replacing the fuel filter thus causeing it to later on become a clogging proble allowing lesser amounts of fuel to reach the system as before causing the reader to say a lean system is being caused so along with the 02 sensor check the 02 sensor,flow sensor,check all your gaskets,valves,etc for leaks you should check fuel lines for leaking the fuel filter for clogging and check oil stats and other fluids that may cause a lesser running value.