05 lx bank 2 misfire after fixing oxygen sensors.

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badreble149

badreble149

Joined
Oct 11, 2022
Threads
8
Messages
21
Location
salt lake city utah
Hey I’ve got a 05 lx470 and I’ve been having a misfire on cylinders 1,3,5,7 for the past bit. Truck runs horribly super rough idle, won’t go above 3k rpm’s, and generally undrivable now. A few weeks ago replaced my cats/broken exhaust bolts, and noticed my upstream o2 sensor wiring was charred. So I spliced in new wire. I then got misfires on cylinders 1,3,5,7. After trying new Oem oxygen sensors all around. Different ways of splicing I got a new to me 05 lx470 engine harness. After swapping the new harness in I am still getting the same issues. I plugged the truck into techstream and my oxygen sensors on bank 1 are still not changing voltage.
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Is it possible while welding nuts onto my broken exhaust bolts I fried the ecu even though I disconnected the battery? That’s the only thing I can possibly think of now. The truck did come with autozone ignition coils in it, and I have heard those can cause weird issues, but I don’t believe that would be related to the weird oxygen sensors issues. Any help would be very appreciated thanks.
 
Trunk Monkey said:
What ECU codes are you getting?
Click to expand...
P0301 p0303 p0305 p0307

badreble149 said:
Hey I’ve got a 05 lx470 and I’ve been having a misfire on cylinders 1,3,5,7 for the past bit. Truck runs horribly super rough idle, won’t go above 3k rpm’s, and generally undrivable now. A few weeks ago replaced my cats/broken exhaust bolts, and noticed my upstream o2 sensor wiring was charred. So I spliced in new wire. I then got misfires on cylinders 1,3,5,7. After trying new Oem oxygen sensors all around. Different ways of splicing I got a new to me 05 lx470 engine harness. After swapping the new harness in I am still getting the same issues. I plugged the truck into techstream and my oxygen sensors on bank 1 are still not changing voltage. View attachment 4099512View attachment 4099513
Is it possible while welding nuts onto my broken exhaust bolts I fried the ecu even though I disconnected the battery? That’s the only thing I can possibly think of now. The truck did come with autozone ignition coils in it, and I have heard those can cause weird issues, but I don’t believe that would be related to the weird oxygen sensors issues. Any help would be very appreciated thanks.
Click to expand...
Hold on I just realized I’m getting low voltage on bank 2 o2 sensors. But bank 1 is cylinders 1,3,5,7 right?
 
badreble149 said:
P0301 p0303 p0305 p0307


Hold on I just realized I’m getting low voltage on bank 2 o2 sensors. But bank 1 is cylinders 1,3,5,7 right?
Click to expand...
That's correct - bank 1 is is the odd cylinders (drivers side).
 
Bank 1 cam, may be out of time. Happens if, belt jump or cam knock pin sheared off.
A compression test "may" be revealing, if timing off significantly.
 
Will it run with the O2 sensors disconnected?
It should go into a fault mode but does that change what you read from the ECU?
 
So after putting in a new to me wiring harness, ecu, another used set of o2s I got from a buddy, and another set of used coils I’m still having the same issues. Checked my timing and all seems okish? Bank 2 seems a little off but I’m not 100% sure, as when I did the timing belt on my 3.4 it was about this close. And she’s been running strong for years now.
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I have not done a compression test yet, but will do one tomorrow after work. As well as pulling the valve covers to see if anything has gone wrong. I did try unplugging the my 1st cylinder coil pack for the fun of it and I got no change. Wich was weird. I did also verify I am getting spark to every cylinder. If anyone has any ideas what this could be please share, I’m about ready burn this sob down for the insurance money
 
2001LC said:
Bank 1 cam, may be out of time. Happens if, belt jump or cam knock pin sheared off.
A compression test "may" be revealing, if timing off significantly.
Click to expand...
That’s what I’m thinking but I find it odd these problems started after I fixed my exhaust leaks, and o2 wiring. I think I’ll tear everything apart now tho lol
 
badreble149 said:
That’s what I’m thinking but I find it odd these problems started after I fixed my exhaust leaks, and o2 wiring. I think I’ll tear everything apart now tho lol
Click to expand...
Typically issue just after a service and not before. Is related to that service. But not always!
I would have done compression at operating temp. But cold can still be revealing.
I would have also. Pulled one fuel injector wire housing block off, at a time. While engine warming up. Watching for RPM drops or not.

It appears your timing is off ~1/2 degree. Angle of camera, can make timing mark look off. Seems your camera angle, looks good. So something not right.

I can see BK1 cam knock pin. BK2 is not as clear. But both appear to bet recessed, as they should be. In one 4.7L, where BK2 P030- on all cylinders of that bank. Compress dead on that bank. Knock pin was sheared. It was due to a botch timing belt job, where BK2 cam sprocket bolt was not torque. It also showed timing off, just a tad. The clue that lead me to look closer at cam knock pin. Was one was recessed, one was out touching cam bolt washer head.
See post #35 for pictures of knock pin, and more later in thread.
2001LC

Thread 'Timing belt job just done. Blown engine or savable? This is interesting guys!'

Happy 2020 all.

Well, I spent last day of 2019, inspecting a 2005 LC w/~200K, that was towed to me. That had a Timing Belt installed a few days before coming to me

Let me know your thoughts:
Blown engine from interference or is there hope?​
  • Also what do you think happened?
Skip story and go to items 1-15 if you'd just like to just get to the data.

Here's the story. I received an email from Cairo, He was responding to a CL ad I posted for 2UZ engines and parts. Subsequently speaking with Cairo I learned, he had purchased a clean 2005 LC w/~200K miles about 30 days...
  • Wow
 
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