Know the code

[GangsterOfLove]

I am new to using codes to troubleshoot engines so I'm hoping someone will help me out here.

2000 4Runner, 4 cyl engine. 179K miles. CEL is on. Down on power, idles rough. Reset the codes and it runs better for a while until the CEL comes back on.

Code is P0325 - knock sensor. Looks straightforward - there is a troubleshooting procedure for the sensor. I assume I remove it, test it and if it is bad then I replace it. The next step in the procedure says that if the sensor is good then I replace the ECM. Is this what I think it is? The central computer? Do these go bad? (!)

Besides reading codes, the scanner I got (ieGeek connected to "Dash Command" on my phone) has a function called "Readiness monitors". 3 are "complete" (Misfire monitoring, Fuel system monitoring, Comprehensive component) and 5 are "incomplete (Catalyst monitoring, Evaporative system, Oxygen sensor, Oxygen sensor heat and EGR system monitoring) are all shown as "incomplete".

What does it mean when these monitors are "incomplete?

Thanks!

 

[zacattack20]

A lot of times that code comes up it tends to be the wiring connected to the sensors and not the sensor it self, although it could be the sensor as well. It gets brittle with the heat.

Did you clear the code? Every time you do it clears the monitors and they will be reset and become complete after driving around for a little while. They only really matter when you go to get a smog check for your truck.

 

[GangsterOfLove]

I'm not so sure that's true about this code. I read that when you get a knock sensor code it retards the timing to the max.

The way it runs (and shifts) would tend to verify that.

 

[zacattack20]

Now I see you have the 4 cylinder which I'm not too sure about. But yeah for the 6 cylinder a lot of times a knock sensor code could be the wire harness.

 

[GangsterOfLove]

I think I've figured out why I get the CEL and the code for a bad knock sensor:



That silver piece of speaker wire is connected to the wire that is supposed to connect to the knock sensor. Connection is via "twist and tape". Ugh. Lord knows what it looks like at the sensor itself but I'm pretty sure I wont like that either. Also, the blue wire above the tape connection is a piece of what appears to be Cat5 ethernet cable spliced in to the line for one of the injectors. That one got crimped butt splices but I don't think much of that method either.

The truck is under warranty and the dealer says he will have his "smog mechanic" fix it. Being as his "smog mechanic" made the hack in the first place I think I will take it somewhere else or buy the stuff to get it up off the ground (you have to pull the starter to get to the sensor) and do it myself.

 

[PoshSnoop]

wow. that's worse than duct tape and baling wire.