SBKoun

Hello everyone!

This is my first post and I was hoping for some advice (All is welcome).

My check-engine light has been flashing and I have been losing power/slows down as I continue to accelerate. This has never happened before, and since I have a long commute home I decided to turn around and park it at work. Thankfully there is a lexus dealership 5 minutes away. The problem is they slap me with a $95-99 diagnostic fee.

Google/Forums tell me it's possibly my cylinders misfiring and I may need to replace all 6 of my spark plugs. At the worst case it could point to my catalytic converter..(That sounds expensive).

My plan is to take it to autozone (have them run a free scan), buy the spark plugs and drive to the Lexus dealership and have them install it for me to avoid the diagnostic fee. They have already agreed to waive it if I simply ask them to install something so long as I do not give them a terrible time if it doesn't fix the issue (since they didn't personally diagnose anything themselves).

Thank you all for reading and have a wonderful day.

hypervish

Welcome to Club Lexus!

Please don't start throwing parts at it, get the codes read first. It's more likely a issue with the coils, rather than the spark plugs. But, again no way to know without codes. You can simply swap the coils around once you retrieve the codes to see if the code moves to another bank with the bad coil. This will confirm the issue before you spend ANY money!

SBKoun

Thank you for the welcome hypervish! Great to be here.

That's great advice, I will get the codes and post it on here soon. Glad to hear coils are easy to swap, hopefully the price tag isn't too bad either.

Thanks,

Baetke

For less $ than the dealer wants to charge you for a diagnosis you can buy your own code reader. Keep in mind that the code reader only tells you what type of fault occured and why, not what part to change. For that you need an understanding of what the codes mean and how your engine and its systems work to properly diagnose the problem. If you don't have that knowlege, there are plenty of folks on this forum who do.

Also, if your check engine light is flashing it is telling you that continued operation is likely to cause serious damage. A steady light means something is out of tolerance but not an immediate threat to the health of your engine.

SBKoun

Apologies for the orientation of the photo. Uploaded from my phone.

Baetke

These codes all make sense with one-another. The P0300 is a multiple misfire code caused by misfires on cylinder 2 (P0302), cylinder 4(P0304), and cylinder 6(P0306) all located on Bank 2. P1153 is a circuit malfunction on the Bank 2 oxygen sensor and P1155 is a heater circuit failure on the same sensor.
Step 1: check to make sure the wiring harness is properly connected to the sensor.
Step 2: If you are really familiar with A/F sensors and a voltmeter, check the for continuity of the heater in the sensor to see if it burned out. Also check for power and ground from the harness to the heater. WARNING: if you are not absolutely confident in your ability to do this right, skip to step 3. You can ruin a good A/F sensor with an ohmeter if you are not careful.
Step 3: replace your Bank 2 A/F sensor. Use ONLY OEM sensor, the aftermarket ones have been proven over and over again to not work!
This also explains the flashing check engine light since this is a primary emissions system and a malfunction could potentially ruin your catalytic converter.

salimshah

Welcome to CL.
Please read the sticky threads .. specially Having problems start here.

When you go to the dealer or any auto shop they have their hourly labor rates posted. Diagnosis and repair are all billed as 'labor rate'. If you go to Lexus for diagnosis ONLY then they will charge you diagnosis fee ... which can be for 1 min to read the codes with OBD. You have to ask the service writer to see if you give them OK to repair would they roll over the diagnosis fee to labor rate. I would very much advice against the service where you tell them what to do. Then you assume the responsibility of wrong/good diagnosis.

Salim