sugarspotz

Are there any recommendations for code readers that are more descriptive or work better with Lexus? I see there are wireless ones and some that have live readings for misfires etc.

Any diagrams for firing sequence?

Recommendations on spark plug and wire brands. Anything truly an upgrade in performance or gas economy vs denso?

Can anyone tell me where the negative body ground wire goes on the left side of the engine from the sway bar to??? I found the negative and positive double ground together on the radiator top on the engine. My body control module isn't working right for years now, mirrors, foot well, seat memory, and console lighting. The Lexus diagram shows the area under manifold on the left side but the bolt doesn't look like the negative L bracket fits there.


I have dreaded P0171 and P0174 so non descriptive when its misfiring and the air to fuel inst right! Hunt and peck it is. Found a great write up which includes every seal and sensor I will have to change eventually. Most of the sensors I have already done. At this point I am finding all the other mechanics ****** ups and correcting them to get to the actual problem as the codes change. Trying to do everything possible that's not buried under the sway bar. I've been chasing my *** on the rough idle with different mechanics for a few years to the point I have given up. Now springs new hope as this car is old enough to find youtubes videos and write ups. If I cant get the air to fuel back to a smooth idle I will not be investing into a new paint job or the 2k in 200K maintenance. at this point if i give it gas to 800 rpm it smoothes out like it should be.

https://www.clublexus.com/forums/rx-...174-codes.html

Arsenii

Hello,

Probably the best OBD-II scan tool for Toyota/Lexus cars is Mini VCI cable that you can get here. It allows you to scan every electronic module in the car, and besides that, it can also re-program some of the car's functionality. Long story short, it is basically the same tool Toyota uses to diagnose your car, but they ask twice the price of that cable for some reason..

Personally, I am using NGK Iridium spark plugs, it seems like those work better that standard Denso ones. However, my car is a 2000 Lexus ES300, which already has VVT-i system. Since you still have wires for the spark plugs in the back, I would assume that your car is pre-2000, hence why you need Double Platinum spark plugs, so maybe you should try NGK BKR6EKPB-11. You can also get NGK wires, Part Number is NGK RC-TE65.
Toyota forum states that the firing order on a wasted spark 1MZ-FE is: 1-4,2-5,3-6.

About Ground wires - can you share a picture of what exactly do you mean? It is very hard to figure out without some kind of visual..

And lastly, your DTC codes - here is a link to a Toyota Diagnostics Manual, look for page 05-66, it shows you details on how to properly diagnose your issue. Generally those are caused by MAF sensor, vacuum leak or a bad fuel injection system. I think that your rough idle issue is caused by those two codes, so give that manual a shot..

Hope this helps and best of luck!

sugarspotz

Arsenii

It is the ground wire that comes from the chassis, near the PS reservoir, to the radiator spout, just like you showed on the photo, and, in my case, to the intake plenum. Don't know if you have that other end of the wire, since you have the plastic intake.

Also, it seems like your wire's isolation is a bit torn, so I would suggest to replace it. The problem is that I doubt you can buy it from Toyota, I have the same problem in my car, and spent ~30 minutes at the dealer trying to explain what I need to no avail. It is considering the fact that I made a crucial mistake of saying that I am looking for parts on a Lexus at Toyota dealer, which got me into a 6 minute debate that Toyota doesn't have parts that I need and therefore should go visit Lexus dealer instead, which is twice as far away. When I was finally able to convey that ES300 has the same basic construction as Toyota Avalon, an employee showed me a diagram that didn't have those wires. That got me into yet another debate, after which we went over all the materials for Camry and Avalon that Toyota has to offer, and didn't find any remnants of it anywhere.. So I gave up and bought just a piece of 10-gauge wire with some ring terminals.




Speaking of plastic intake plenum - it appeared only after year 2002. It means that your car no longer has a wasted spark system, hence why it no longer has high-voltage wires - it has all six coils. It also means that you can no longer use Platinum spark plugs, you need to get Iridium ones.
Can you specify the exact year of your car?

Hope this helps and best of luck!

Dschwartz

I'm experimenting with BlueDriver. I'm not sure if any readers will fully detail the fix, or process to fix. These guys www.autocodes.com at least gives you a clue.

sugarspotz

2002 es300 vtti

took it to a lexus specialist time to look for another car the coolant pan is cracked on top of the seals and struts and motor mounts steering rack etc. i gave up as i couldn't find a good mechanic at this point i have to rebuild the engine seals to get another 100K

They did place the ground wire but anchored it to a bolt through the plastic manifold. doesn't seem right as it should be on the engine? i guess it goes under them manifold so you cant get to it? someone double grounded the body ground wires to the point on the radiator and pulled the computer relay with out disconnecting the negative battery cable. so is it possible they fried the computer? Lexus specialist says he has never changed a computer on these cars.

Dschwartz

I recently watched a show on replacing the computer, looked easy.