CEL: Code 32 Air Flow Sensor and 52 is Knock Sensor
 

My check engine light came on the other morning on the way to work. Hadn't gotten around to pulling the codes until this evening. However, yesterday replaced the plugs, distributor cap and rotor. Plugs looked good for being a yr old. The distributor cap and rotor were another story. The rotor was so badly pitted it was a wonder I was getting a spark. After replacing these I pulled the EFI fuse to reset the computer. Still getting a
CEL.

On to the codes. 32 is Air Flow Sensor and 52 is the knock sensor. I'm going to clean the Air Flow here in a few but what about the know sensor? I looked in the FSM and didn't find them. Haynes shows one near the dipstick. I looked and didn't see it. Are these easy to replace or am I better of letting the local shop do it? Or....is it something else?

Looking at my symptoms and reading the FSM I'm leaning more towards the knock sensors.

Hey! The knock sensor on the 3.0 V6 (3vz-e) is located under the lower intake manifold in the middle of the "V". To get to it, you will have to remove the plenum, fuel rails, intake manifold, and drain the radiator. You may also have to take the tension off the timing belt in order to take the idler pulley off of the intake manifold (that's what the haynes manual says to do and that's what I did, but you may be able to skip this--not sure though) I checked out every parts store around here and only place that had it was Pep-Boys for $160. Get it from the dealer. I wish I did. Almost the same price and get the knock sensor wire too (around $14). Real bugger to get too, that's for sure!

But, before you go tearing into things, make sure the knock sensor wire is securely plugged into the wiring harness and not all buggered up. If you look down on your engine and slightly below and to the rear of the throttle body, you will see the knock sensor wire coming up in a notch between the head and intake manifold. Make sure it is plugged in tight and is a clean connection. I know a few members here have solved the code 52 problem by cleaning the connection. Woth a try!

I hear there a way to jurry-rig a chevy knock sensor in using an adapter, but not sure the details on that. I do know it's much cheaper though. Might find it with a search maybe.

Well, hope that helps.
Have fun all. :)
Daniel

If I have to pull the intake and possibly get at the timing belt what other "minor" things should I do? Timing belt, injector clean, etc.

You may want to put in a waterpump. They sit behind the timing belt, and are easy to get to once the belt is off. They are fairly cheap, so you may want to just go ahead and replace it since they do go out sooner or later. You should also replace the thermostate. Replace one or both of your timing belt idler pullies if they look bad and don't spin freely. If you have never done this before, than there is a good chance you will need some, especially with the amount of miles on that truck. Also replace the PCV valve and hose (if it needs it) on the passenger side valve cover. If you do pull of the timing belt, you may want to consider replacing the front oil seal on the crank shaft if it is leaking.

That's all I can think up right off the top of my head other than the various gaskets and O rings.

I didn't clean my injectors, but honestly, I didn't even think about it. I did have my plenum cleaned though. Just take it to a shop and they can soak it in some cleaner overnight for you.

Well, have fun. :)
Daniel