1998 LX470, 265k miles. New to me, so I've been baselining even though it runs and drives great. Not much service done by the prior owner other than oil changes afaik.
Last night I decided to clean the MAF sensor and change the spark plugs. One mishap during the plug change - accidentally set my ratchet across the battery terminals for a fraction of a second. Negative battery cable was disconnected at the time so likely no issues from that.
Finished the job and fired it up greeted with an instant misfire code on cylinder 4 and shaking. Took everything apart and put it back together. My wire on coil for cylinder 4 wasn't pushed on all the way. Great! That must be it. Fired it up and felt some shaking, multiple misfire codes pending status (P300, P303, P306). Went to bed for the night.
This morning - clear codes, fire it up again and testdrive. MIL light blinking and misfiring still. This time codes P300, P303, P304, and P306. Take it back home and tear it apart again. P306 seemed to be coming on first and most often, so I swapped the coil on it with Cylinder 2. This time got codes P300, P303, P305, and P306.
Take it apart again. Inspect plugs and coils. All 8 are Toyota/Denso but two different part numbers - one P/N seems to have superseded another based on some looking at online parts stores. One coil was missing the rubber grommet. Also noticed spark plugs were Denso but not the OEM part number. Gap spec was 1.0 mm vs. 1.1 mm.
Took a trip to the parts store for OEM plugs and also picked up a NAPA brand coil so I could borrow its rubber grommet. Got a feeler gauge and checked all the gaps. All good to go. Went home and tore it apart again and put the new plugs in along with the coil grommet. Checked MAF resistance - slightly low for the 68F spec in the FSM but interpolated and it was in range for the 80F temperature in the airbox.
Put it all back together and fired it up. Still shaking. Misfire code P306 pending after a few minutes. Cleared it and went driving. During the drive I get P0300, P0303, and P0306. I've visually checked all hoses and wires.
Looking for help, have searched the forums and read through lots of ideas and tried a lot of things. Where to from here? Could one bad coil be causing codes on multiple cylinders? Is it possible I have multiple bad coils that weren't there before the plug change? Did I screw up the MAF sensor cleaning it with CRC? Is it possible I crossthreaded a plug or one is not sealing and is causing misfire codes on multiple cylinders? Did I fry something else with my ratchet on the battery trick? Should I throw the NAPA plug in cylinder 6 and see what happens?
Last night I decided to clean the MAF sensor and change the spark plugs. One mishap during the plug change - accidentally set my ratchet across the battery terminals for a fraction of a second. Negative battery cable was disconnected at the time so likely no issues from that.
Finished the job and fired it up greeted with an instant misfire code on cylinder 4 and shaking. Took everything apart and put it back together. My wire on coil for cylinder 4 wasn't pushed on all the way. Great! That must be it. Fired it up and felt some shaking, multiple misfire codes pending status (P300, P303, P306). Went to bed for the night.
This morning - clear codes, fire it up again and testdrive. MIL light blinking and misfiring still. This time codes P300, P303, P304, and P306. Take it back home and tear it apart again. P306 seemed to be coming on first and most often, so I swapped the coil on it with Cylinder 2. This time got codes P300, P303, P305, and P306.
Take it apart again. Inspect plugs and coils. All 8 are Toyota/Denso but two different part numbers - one P/N seems to have superseded another based on some looking at online parts stores. One coil was missing the rubber grommet. Also noticed spark plugs were Denso but not the OEM part number. Gap spec was 1.0 mm vs. 1.1 mm.
Took a trip to the parts store for OEM plugs and also picked up a NAPA brand coil so I could borrow its rubber grommet. Got a feeler gauge and checked all the gaps. All good to go. Went home and tore it apart again and put the new plugs in along with the coil grommet. Checked MAF resistance - slightly low for the 68F spec in the FSM but interpolated and it was in range for the 80F temperature in the airbox.
Put it all back together and fired it up. Still shaking. Misfire code P306 pending after a few minutes. Cleared it and went driving. During the drive I get P0300, P0303, and P0306. I've visually checked all hoses and wires.
Looking for help, have searched the forums and read through lots of ideas and tried a lot of things. Where to from here? Could one bad coil be causing codes on multiple cylinders? Is it possible I have multiple bad coils that weren't there before the plug change? Did I screw up the MAF sensor cleaning it with CRC? Is it possible I crossthreaded a plug or one is not sealing and is causing misfire codes on multiple cylinders? Did I fry something else with my ratchet on the battery trick? Should I throw the NAPA plug in cylinder 6 and see what happens?