Here is the deal; idle is nice and smooth in neutral and park. When I shift into gear (including reverse) it gets as rough as a tractor. Once I start driving it is smooth.

I threw the 4runner into diagnostic mode and got codes 4, 5 and 6. Water thermo sensor, o2 and RPM respectively.

Thermo sensor checked out good (.3k ohms)

I don't know how to check the o2 sensor.

The plugs are new as of today. The wires, rotor and cap are a few days old. Timing is at 5, and 750 rpm at idle.

I need your brains Mine hurts. I have this, and an 85 Monte Carlo SS I am working on that has just been kicking my butt.

 

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I am trying a few things before I purchase any parts, plus I still can't find any info on testing the 02 sensor.

I burped the hell out of the coolant system, and I am resetting the PCM (I pulled the ignition fuse instead of the efi fuse last night, lol).

We'll see where this rabbit hole leads.

 

Well, since no one is offering insight...

I am starting to think I have a head gasket leak. I am thinking exhaust from the cylinder is escaping into the crank case and coolant passages giving me excessive pressure in both. I should have a leak down test kit in a few days to determine if I have a gasket leak or not. Compression test read between 200 and 205 for all cylinders and the oil has no water in it as of yet.

Anyone have any experience with error code 6? Or know how to test the O2 sensor?

 

I dont have my manual with me but a code 6 on the web says RPM signal (Crank Angle Pulse). My wife has the truck at work and that is where my manual is. So I can get it for you later to be more helpful. I dont really know on testing the O2 sensor. I just got into the habit of replacing them. I have ordered around five O2 sensors from sparkplugs.com for several different trucks and have had good luck with them and they are quite a bit cheaper.

 

Crank angle pulse... there is no crank sensor on these motors, unless it is talking about the magnetic "pickup" in the distributor.

 

If the 02 sensor is original or has over 50.000 miles on it, then it needs to be replaced. When you replace it buy a Denso 02 sensor, Bosch 02 sensors don`t work well in toyotas.

 

It has less than 100 miles on it, and is a Denso brand sensor.

 

Well, I just got my leak down test kit in the mail. I have a "blown head gasket". I actually suspect the head itself (replaced head gasket when I installed the new timing chain cover), and for the price of a better virgin head and better cam I might as well go that route for replacement.

Anyone know where to get replacement window sweeps for the rear window? Or how long Marlin Crawler takes to get back to customer inquiries? Maybe the availability of w56's and projected price range (for swap purposes)?