I have had my van for 7 years and it has coded right bank lean after 2 hours of highway driving since I bought it. Now it is starting to throw the check engine light after about 30 to 45 min.

The light will come on and off several times, and then stay on until I shut it off and let it sit for about 15 min.

I "think" I changed the O2 sensor at the cat. several years ago, but that could have been my truck,(I'm getting old and can't remember what I'm forgetting).

If in fact it is only the right bank, would injector seals be a good place to start or is there other things I should look at first.

Thanks.

 

You should pull the codes again to make sure the CEL isn't being caused by something else. If you don't have a scanner, you can do it yourself pretty easily: Pulling EEC-IV Codes


Clogged fuel injectors could cause a lean condition. Have you tried cleaning the fuel system ...running a few bottles of good FI cleaner through?

Intake/gasket leaks might also be worth considering, as well. Maybe you can try re-torquing the intake bolts.

 

I have used all kinds of fuel cleaner on a fairly regular basis through the years, I have also used throttle body, intake & valve cleaner that you spray in the throttle body in short squirts while the engine is running.

All of this has not helped the light problem any, but the van does run good. I didn't drive the van for about seven months, and that is when the light started coming on after running maybe 30 - 45 minutes instead of two to three hours.

I was thinking that the sitting may have hardened the injector o-rings further causing them to leak more air around them.

I used to work on VW Rabbits that were notorious for hard injector o-rings that caused rough idle and lean conditions. I was wondering if this was possible with Ford's fuel rail system.

I have checked all vacuum lines and the brake booster and they are not leaking.

Any ideas will be appreciated.

Thanks.

 

If it sez 'right bank', then you have to have 2 O2 sensors.. one in each exhaust. Try swapping the sensors side to side and see if the problem follows. The O2 sensor is a 'low = = lean' value. About .2 volts to abt .9v when rich. So, if it quits working, it can throw a code.. a rong one at that. A bad O2 can also tell you you need to replace a catalyst that is 'below efficiency' when in fact, the O2 just doesn't know that the cat is working fine.
There is a little cone shaped screen in the input side of the injectors.. that could be full of crud after all these years. If you pull the fuel rail, you probably would have to replace the 'hats', too, as the plastic gets very brittle. I have a part # somewhere if you cannot find it. I'd replace the O-rings if I pulled the inj at that age/mileage...
tom

 

On the back of the passenger side head look for a ground wire. This is for the EFI for the pass. side. When the wire gets loose or breaks off, it will cause the problems you are describing.