My word I haven't been here in two and a half years and this great site is even better than before. Congratulations to the administration for a spectacular job in keeping this site up.

I'm in need of a little information and hope someone can help me out.

My 98 Lariat with, the Triton engine, (not sure at the moment of the size) began to run rough recently and then the "check engine" light came on. My son put it on the computer and got this message, "Bank 1 & 2 system too lean. Oxygen sensor before the catalyctic converter" or something like that. I want to get the replacement part and have a friend install it (I know! Cheap bastage!) but want to make sure we replace the right one. Where is it? And will the computer need to be reset?

Thanks in advance for any assistance. ennis

 

fourhour,

Just because you pulled those trouble codes, doesn't really mean your o2 sensors are bad. Both at the same time! I doubt it, that code tells you that both 1&2 banks are running lean (just what they are suppose to do) if you have a problem somewhere else.

I'd check the intake track (from the air cleaner to the intake manifold gaskets) for a leak or bad component. Could even be a fuel problem. (injectors,fuel pump, regulator)

Just my 2 cents worth!
Good luck.

Gene

 

Check for Vacuum leaks,, pcv valve lines are bad for cracking, and also behind the battery there are vac lines that crack.

 

Forgot to mention that it runs crappy sporadically, most noticably stopped at traffic lights. Thanks for your input. ennis

 

I had the same problem last week. Banks one and two were lean and it would not idle at a stop light. I just ended up replacing all of the lines that connect with the pcv valve. Save the time and replace all of it. You will have to go to a dealership to get the parts though! It was only 15 bucks for everything.
One of the connections is towards the back of the engine, you can check for a leak by spraying carb clear towards the back of the engine. If you have a leak it will idle up.