Check Engine Light

[joshuaj0214]

I am running a 98 5.0 in my sport and on monday it threw a CEL. I checked it with the scanner and it says Bank 1 and 2 lean. Im guessing its starved of fuel, but it runs perfectly and doesn't miss at all. Any ideas?

 

[nastygeorge59]

Hi Josh, if you have a lean flag, it means there is to much air, maybe an air or vacuum leak some where. The system is trying to compensate for this. Look for cracked lines, air boot, etc.

 

[joshuaj0214]

Good call, thanks for the reply!

 

[nastygeorge59]

No problem. Good Luck!

 

[ERUSH97XLT]

Hi Josh!

My explorer threw the same codes. Check out this thread:

http://www.explorerforum.com/forums/showthread.php?t=225969

From what I've learned, lean codes can be generated by a number of things:

1. If you look at the "fuel" side of things: maybe a clogged fuel filter, water in the system, bad gas, and/or a dirty fuel system can slightly starve the engine of fuel beyond correctable limits.

2. If you look at the "air" side of things: as nastygeorge said, check for vacuum leaks (however small, a little amount of extra air will trip a lean code). I've beat my head against a wall trying to find some before, so be thorough; use a gauge and carb cleaner to be sure.

3. A lot of times, its faulty readings from a sensor (i.e. MAF, Oxygen Sensors, etc.).

Personally, a quick and dirty method would be to clean your MAF and IAC. Then check your vacuum and fuel pressure. If you still get codes after that, have it hooked up to a scanner to see what's going on electronically.

Hope this helps.

ERUSH

 

[joshuaj0214]

Thanks for the great starting points guys. Today I noticed the light went out on its own after starting the truck. I hope it was just a fluke and I'm gonna keep my fingers crossed that it stays out. Thanks again.

 

[budwich]

probably not... since you have done nothing (actually restarting a certain number of cycles will cause the light to go out for those types of codes). It will likely relight again.

 

[ERUSH97XLT]

What's the status on your lean codes and and gas mileage?

 

[joshuaj0214]

It has not come back on yet, but I haven't hooked up the scanner again to see if their still in the system. Gas milage is the same, bad, 12 mpg that I've gotten since the engine swap!

 

[tripplec]

Temperature?

It has not come back on yet, but I haven't hooked up the scanner again to see if their still in the system. Gas milage is the same, bad, 12 mpg that I've gotten since the engine swap!

Was it really cold? If so maybe ice in the line or fuel filter causing a restriction. Otherwise fuel filter mostly cloged. How is it on the highway, and accellerating on the highway. Poor response or bogged down are also filter indicators and if really bad you idle and starting will eventually be affected.

Stick to name brand gas, they are cleaner and have cleaning additives in them and most also have antifreeze in the mix for the winter.

 

[joshuaj0214]

I haven't had a single issue with drivability. It's not missing or idiling rough or anything like that. I'm hoping it was just a bad batch of fuel! I have put about 180 miles on it and the light still has not come back on. Thanks for the input!

 

[ERUSH97XLT]

Hey Josh,

Let us know if your feul economy is still bad (unless 12 mpg is the standard for your 302). Then I think a good scan is in order to see what's going on electronically.

ERUSH

 

[joshuaj0214]

Hey Josh,

Let us know if your feul economy is still bad (unless 12 mpg is the standard for your 302). ERUSH

Sorry to say it, but thats about average!

I just went to North Carolina for the holidays and I got a all time best so far of 15.89 mpg. I have lightened up a little on my driving style and I am now getting about 13-13.5 mpg.

 

[ERUSH97XLT]

Oh, wow! 12 mpg is the norm!? Geez...

If you're still getting lean codes and your gas mileage drops significantly (in your case, say, 8-10mpg), something electrical or mechanical is going wrong, not just bad gas. I know that sounded obvious, but save youself the headache and get it scanned by a mechanic who knows their way around the OBD II diagnostic systems and can interpret what happening electronically. I've beat my head against a wall trying to solve this very issue with my explorer using conventional gauges and multimeters. The only way to see what your car is thinking is to get it scanned.

What do you all think?

Hope this helps, and Good Luck!

ERUSH

 

[joshuaj0214]

Thanks for all of your input Erush, it helps to hear others ideas. A friend of mine is a ASE tech and owns a good Snap-on scanner. I may get him to go thru it just for the hell of it. I cant wait to find out if the 4406 transfer case will fit. I will save a few mpg's being able to select 2wd instead of powering thru all 4 wheels!