K&N = Engine Check Light?

[psychos2]

if it is gettting a code for the maf then that is the problem. not the intake gaskets.either a wire is pulled out or a bent prong or it is dirty or covered in oil.the other sensor is more than likely an air temp sensor. shawn

[mbeach]

if it is gettting a code for the maf then that is the problem. not the intake gaskets.

Not necessarily.
The engine only has one way of determining the correct a/f ratio before the burn -that's the MAF. After the burn you have 2/4 O2 sensors.

If there's a leak (air) between these sensors, the ECU can pick the most likely item. It finds the fault at the O2 sensorS (all of them). Since it is unlikely that both banks would simultaneously go lean, the ECU has the sense to choose the component which measures the incoming air to begin with.

Disconnect the intake tube from the throttle body and I'll bet that you throw a MAF code.

[JAFO]

Ok, I have found what happened. While I was installing the headlights, before I put in the K&N, I had the cover off the air box but not disconnected from the MAF or tube. I had pushed the air box cover towards the dash and hooked it over the top of the fuid bottle next to the air box to get it out of my way while installing the headlights. I think this is the power steering bottle, I don't recall. Any ways when I did this I was not as carefull as I should have been and it put too much tension on the cable going to the MAF. Upon close examination of the MAF plug I noticed that one of the wires was loose. It actually broke the wire where the pin was crimped on.

Unfortunetly nobody in town as either the right 3-pin replacement plug or wire terminals small enough to fit. So I am going to have to wait until Monday to order a new plug or pin.

[mbeach]

I'm glad that you found the problem.

[JAFO]

Fixed it. I was able to remove the wire terminal and resolder the wire back on.

I put the K&N bask in and no engine check light. I took it for a spin and I can tell the difference. Under accelleration the engine even sounds smoother.

Thanks for all of your help!

BTW, Now that it's dark I'm going to go try out my new PIAA Xtreme White headlights.

[psychos2]

Not necessarily.
The engine only has one way of determining the correct a/f ratio before the burn -that's the MAF. After the burn you have 2/4 O2 sensors.

If there's a leak (air) between these sensors, the ECU can pick the most likely item. It finds the fault at the O2 sensorS (all of them). Since it is unlikely that both banks would simultaneously go lean, the ECU has the sense to choose the component which measures the incoming air to begin with.

Disconnect the intake tube from the throttle body and I'll bet that you throw a MAF code.

sorry, but that is not how it works.the computer has parameters and when it is outside the parameters it throws a code for that sensor.and the maf is not the only sensor it uses to determine a/f ratio. it also uses the air temp sensor . i agree you would get a check engine light if you disconnect the intake tube but it would not be because it picks the most likely sensor. it would be because it knows there is oxygen coming in (engine cannot run without it) but it is not getting a reading from the maf saying there is air coming in. and you would more than likely get other codes due to the maf not showing air coming in. besides when something is functioning properly before you install something and is not working properly after there is a very big chance (probably 99.9%) that you screwed something up. like pulling the wire to hard. when diagnosing problems you start with the simplest things first. shawn

[mbeach]

If you read my first post, you'll notice that I said to give the intake manifold gaskets a look AFTER you're done with the MAF.

IAT sensor just helps the ECU determine air density (based on temp.). Unmetered air entering the engine (and being detected post-burn) will always point to the MAF. The intake gasket leaks are usually intermittent enough that they won't throw a code before driveability suffers. In fact, both of my trucks sprung leaks at the intake gaskets without a code at all.

If you rely solely on CELs to diagnose problems you're in for some long nights. Check the obvious, like you said, then check the likely.
If he had ruled out the MAF (could've just checked for continuity at the engine side of the sensor), where should he go next?

Having spent a number of years behind the wheel of a tuned scooby, I learned that CELs are only a guide, and not the be-all-end-all of engine diagnostics. Your statement "...if getting a code for the MAF then that is the problem..." smacks of finality, and will lead to headaches if you start replacing sensors unnecessarily.

[whtzmbi]

I just installed a K&N filter with no problem...the CEL has not come on at all (yet) I hope it doesn't either

[JAFO]

I just installed a K&N filter with no problem...the CEL has not come on at all (yet) I hope it doesn't either

You should be good. My problem was I wasn't carefull with the MAF wire under the intake tube and pulled the wire loose.

Now that the K&N is in I have been contemplating exhaust change. But I can't till my RX-7 is back from getting turboed.