Hello all.
I am new to the forum and I have read a number of the posts on here about other codes, namely the P0330 as I was previously having that code come up, and often, even after clearing it. Occassionally that code was also copled with P0171 and P0174, and P1325 (rarely). A local and well known independant Toyota & Honda mechanic replaced the Knock Sensors, wire harnesses, Intake manifold gasket, and I believe some tubing, which eliminated the P0330 code. At first everything was like no problem ever existed, ran really well and no codes. My prior issue of not being able to always go into overdrive was gone. Then a few days later, CEL and code P1325 came up. I can still go into overdrive however there were a couple of strong jerks while driving about 50, which seems to be misfires.
My vehicle is a 2001 Lexus RX300 that I have had for 7 years, got it when it had 82K miles and now it has 165K. The Ignition Coils went out soon after I got it back then, and I changed those out along with new spark plug wires. Yet now there seems to possibly be another Ignition Coil, #6 per most of what I have heard/read, that the code P1325 is hinting to. Luckily that one is in the front and easy to get to, yet I want to see if anyone else has had this chain of events (or similar) come up and if they think it could be something else like vacuum leak from the recent repair (I honestly am doubting that), or if the Mass Air Flow Sensor is causing it...etc.. The Mass Air Flow sensor i have cleaned out already, and I have done that before as well, a few years ago. Could it be causing this though? Or could it be part of the problem? I have watched some youtube videos as well, one guy showing how to test to see if it is the Ignition Coil by unplugging one and plugging it in to another while the car is running and see if there is change in the engine performance. Seems easy enough, yet I would rather ask people who are big fans of the RX 300 first Gen like I am to see if I should try one thing before thinking maybe I need to replace the Ignition Coil, spark plugs, and/or MAF...
Thank you for your help

 

At this time you have P1325 code .. the rest is history.
Not sure what you mean with new spark plug wires.
Did you change spark plugs? Recommended interval is 110K miles.

Do not perform the following with the car running. Turn it off and take the key out of ignition at wait at least 2-3 minutes before doing anything. [standard operation procedure with RX]

Swap ignition coil from #6 to #2.

Clear the code and start the vehicle and do a test drive if you can. If P1325 comes back then swap #6 spark plug with #2. Repeat and if P1325 comes back again ... take the vehicle to a mechanic.

If the code moves to cylinder #2 then in the first go the ignition coil is bad and if it was in the second go then the spark plug is bad.

I would highly recommend to stay with OEM coil pack and spark plugs.

Salim

 

Thank you! Appreciate your quick reply and details to help.
Sorry, the spark plug wires was supposed to be "spark plugs as well". So yes, I changed out the spark plugs back then and I am guessing it was around 90K miles at that time. I figured if I was going to do the ignition coils, should do the spark plugs too at the same time.
Ok, I didn't think trying to touch this electrical part while the car was running was a smart idea...he was unplugging the wiring harness from the coil to another coil.
Anyway I will definitely try what you suggested. And I was researching parts if I needed to get them, do you know a good website to get OEM parts from?
I know how to do the Ignition Coils and spark plugs, along with some other things. However if you think a mechanic needs to do more than that, please let me know your thoughts.

 

Spark plugs -> just check the owners manual and they can purchased from any place. Just make sure they are reputable sellers and please stick to the make and type as stated in owners manual. Some have tried other brands and with mixed results, but since you are having issues there is no point in adding an unknown in the mix. Iridium plugs come pre-gapped so don't twist the tab.

For coils, get them from Lexus/Toyota on-line dealers. Check with local Lexus parts and decide which is a cheaper option. [some are even on eBay]

The key is diagnosing the problem and not throwing parts at it. If you can't diagnose then look for a professional.

Salim
ps: These days you can't trust the label or markings. So don't fall for the cheapest supplier and pay a bit more if you need to.