Nica400h

Changing out coils/plugs and possibly vc gaskets on an '06 RX400h with 235+k miles. Has anyone used Delphi ignition coils? Rockauto has Denso at $50.79, NGK at $54.79 (both under their standard replacement category), Delphi is listed under their premium category for $43.89. Are they a good alternative to Denso?

Margate330

Welcome to Club Lexus and your 1st post!

LeX2K

No aftermarket coil is as good as original there are levels ranging from okay to terrible. I buy NGK just because it is a trusted name but several people have experienced failures out of the box. Why are you changing coils? If you have no codes then don't touch them. Coils in my 2006 Highlander (same engine) are made by Diamond not Denso.

evident

go with Denso if you can. I have purchased the Denso's from rockauto when i did my spark plug change and they have been chugging along with no issues. I would go with these especially since the labor to replace the rear 3 coils are such a PITA.

with that said, previous owner of my TSX did put a delphi coil on one of my cylinders and i've been driving with it for over 40K miles. the difference is that it takes 5 minutes to replace a coil on that car though so i don't care.

Nica400h

I had misfire code for cylinder 1 and 2, then scanned again an hour later with different scanner and got 2 and 3. It ran rough, definitely misfiring, so, I'm just doing the whole rear bank.

Mesquite77

With the misfires, you may want to do a compression check while the rear plugs are out. You can chase your tail with coils and plugs and not fix anything if one cylinder has low compression, and getting at that rear bank is annoying...

ChemEng

I replaced all coils on my 2007 RX350 with Delphi coil in Jan of 2022. I don't drive my car much... maybe 5000 miles a year. Early this in Feb, I had a check engine light on one night. I checked the code and it was misfire in one cylinder. The next day the light went away on its own and the car ran fine.... I then decided to switch the coil from the cylinder that was reported to be issue to another cylinder to see if the ignition coil was defective. The car has been driving without any issues and no check engine light whatsoever. I don't know what was the reason that cause the check engine light to come on. Since the issue hasn't happened, I'm still happy with the Delphi coils.