Tricks To Pass Emission Test

My 97 Explorer is driving me nuts. It won’t pass the emissions test because it has codes for bank one and bank two running lean. The stupid thing runs fine, but keeps tripping these codes. What can I do?”

Well, quite a few things can cause those two lean codes to pop up. BUT, since you mentioned it’s running perfectly fine, then odds are you have an intake manifold gasket VERY small leak. Other problems that trip that code will generally make the truck run bad. Small vacuum leaks in the intake manifold will often not effect the running in any way you’ll notice. It is a pretty expensive job replacing the intake manifold gaskets, so you might try an old trick first (as long as it runs fine otherwise.) Have the computer reset with a scan tool, then drive on the highway going sixty mph for about thirty miles so the computer system will get itself ready and be able to pass the emissions test. (If you don’t drive it far after resetting the computer, you will fail the test because it will say that there are too many MILS not ready in the vehicle.) Then, if the check engine light doesn’t come back on, quick go and get it inspected. If the leaks are really small, the check engine light may not come on for a while, giving you enough time to get it inspected.