JASON DeMELLO SAVED MY A$$
On the eve of my North Rim - Grand Canyon/Aztec Caves run with VOLHOO, I started the engine of the FJ.
<CHECK ENGINE> light on
When the check engine light goes on, all of the traction control lights come on and it's quite spectacular.
No problem. I have a ScanGauge2. Yes there are error codes, but none correspond to Toyota error codes.
The rig is driving fine. I run down to Auto Zone and plug in their scanner and it shows the following error codes: P043E, P2401, P2402, P2419. They looked them up for me. They only correspond to Mazda and Volkswagens.
The clerk at Auto Zone picked his nose, rubbed his hand through his hair (I'm not kidding - literally) and told me he had "no idea".
So I drove to ToyotaMasters and spoke with my friend, Eric, who broke out his scanner. All it showed was "error".
I hate to bother Jason DeMello, but he's THE genius so I drove to his shop. The diagnosis took all of about three seconds.
For those of you who are knowingly saying "of course that's what it is", keep in mind that I am a functional idiot - relying on gauges and diagnostics to cover my ignorance.
The MAF Sensor plugs in behind the OEM Secondary air filter. Oil from the K & N air filter I was running slowly accreted on the sensor over time. Dust attached itself to the sensor (with a minute quantity of oil on it).
So I dumped the K & N filter in the trash (if anyone wants it, it's in Jason's trash - they have a lifetime guarantee - rush over before they empty the trash tonight) and bought an OEM filter - and will be going with paper filters now. Jason took his air hose and blew out the secondary air filter and was COMPLETELY helpful.
Apparently this has been a problem with Tacomas that ran K & N Filters. Jason said that if the MAF Sensor gets too clogged with dirt, it will shut down the engine and the engine won't restart.
Electronic parts cleaner sprayed liberally on the sensor cleaned it up.
For those of you who run in dust a lot as I do and particularly those who are running a K & N Filter - this is a learning point: Clean your MAF Sensor. Because if it shuts down and you're in the back of beyond you may not know why the engine died and won't restart - and the error codes on your ScanGauge will not reflect the nature of the problem.