NC Inspection: check engine light/engine too lean

[footracer]

My 3rd Gen has has the check engine light on for about 2 years. My mechanic says the reason is "engine too lean" meaning there's not enough oxygen in the exhaust. It could be a faulty/dirty sensor, it could mean a new sensor needs to be purchased, or it could open a whole can of worms. None of which I see coming in less than $300.

In order to pass inspection, NC requires the check engine light to be off.

Someone has mentioned to me that I should detach the ground, reattach, then start the engine and drive to the inspection center and have them inspect (hook up to the 4runner's computer and run a diagnostic) without turning the car off.

Any insight?

 

[glenyoshida]

My 3rd Gen has has the check engine light on for about 2 years. My mechanic says the reason is "engine too lean" meaning there's not enough oxygen in the exhaust. It could be a faulty/dirty sensor, it could mean a new sensor needs to be purchased, or it could open a whole can of worms. None of which I see coming in less than $300.

In order to pass inspection, NC requires the check engine light to be off.

Someone has mentioned to me that I should detach the ground, reattach, then start the engine and drive to the inspection center and have them inspect (hook up to the 4runner's computer and run a diagnostic) without turning the car off.

Any insight?

You might want to try cleaning your MAF (Mass Air Flow) sensor if you haven't done that yet. It's not expensive and it certainly won't hurt to try. Simple tune up stuff as well, such as changing your plugs and/or wires, and air filter.

I'm not sure if turning off the light will do you much good since you are putting out NOx and you might fail the emissions test anyhow.

 

[footracer]

Thanks for the suggestion! I'll try that and see what comes of it.

The 4R passed the NOx emission test. It failed inspection because there's not enough oxygen in the exhaust.

 

[glenyoshida]

Thanks for the suggestion! I'll try that and see what comes of it.

The 4R passed the NOx emission test. It failed inspection because there's not enough oxygen in the exhaust.

I've heard of guys having good luck with Sea Foam engine/injector cleaner as well. The PCV valve tends to get dirty on just about every vehicle that has one.

 

[JohnsD90]

Someone has mentioned to me that I should detach the ground, reattach, then start the engine and drive to the inspection center and have them inspect (hook up to the 4runner's computer and run a diagnostic) without turning the car off.

Any insight?

You cant do it on a 96 or later so your screwed, it worked on my defender but that cause it was a 95, its an auto fail if you do that cause the test will reconize that the system was just reset, u have to run it for like 50-100 miles for it to not pick up on it.

 

[004Gunner]

Just post up the code so we can help you get rid of the issue for good. Cleaning the MAF and inspecting the PCV valve are both good ideas and should be done even if it is unrelated to the check engine light. If it is an exhaust sensor then you can fix it yourself for $200 or less, generally.