Have a CEL producing a code "System too lean bank one" and "system too lean bank two." I cleaned the MAF but still hasn't gone away after 25 miles. I did use cheap gas at the last full up but added some octane booster after the CEL came on. What next step should I take? And is it safe to drive?

Thank you

 

A lean mix is usually an indication of a leak somewhere in the intake side of the engine and the O2 sensors are picking it up. You need to systematically check through the intake side and look for, something like a loose connector on the intake ducts after the MAF or a leak in the intake manifold gasket or even injector seals needing replaced. If all is good there then check the exhaust side for leaks where air is being pulled in before the O2 sensors, something like a defective gasket or (less likely) a leak at the manifold/down pipe connection.

 

Thanks for the info I will give this a try. The light actually came on immediately after an oil change and power steering flush if that is any indication of the issue. Also do you think I should keep it off the road?

 

Unlike a rich mixture where unburnt gas passing into the exhaust can damage the CATs, a lean mix shows that there is to much oxygen. This is unlikely to do much harm, but the system will be trying to compensate and you may experience some rough running, therefore don't plan any long runs until you sort it.

 

Check your oil cap and O RING on dipstick , make sure they sit all the way in , twist dipstick a little making sure , it 's tight .Both lean codes would indicate a vacuum leak which would have been caused by loose oil cap or dipstick.Make sure clamps on intake hoses are secure and tight as well before and after MAF sensor.

 

Had the same issue which caused me to fail emissions. I cleaned the maf and throttle body. Bought some BG44k and shell gas. Not a problem since. Also passed emissions

 

I quit using Shell. Not that there is anything in particular wrong with it, but the whole "clean engine" crap is just that-- crap.. It does not clean anything any better than anyone else. I came the that conclusion after using nothing but shell for the first 75k miles, and determined that it was just as dirty, fouled and in need of throttle body, induction service and everything else.

I have started doing chevron when possible, seeing as techron additive is one of the things recommended by some shops/mechanics. Though, BG44k is all LR recommends, probably because it is harder to get and they can charge more for it.

 

I hear ya brah. Amazon.com actually has the BG44K little cheaper.

 

This is what did it for me. I used RP Max Boost and then filled up with Costco Premium. Light went off right after the fill up.

Thanks everyone!

 

I'd have the injectors cleaned with the BG 210. It runs the engine off the cleaner through the fuel rail with a special device. You'll probably need a shop to do this for you if you don't have the special equipment. I'd have them watch the fuel trims with a live data scanner before, during, and after, to give you and idea if things are getting cleaner in the injectors. (something like this was mentioned by a guy on another forum of how he knows the stuff works).

After that, I'd toss a can of BG 208 (the BG44K) in the tank.