Important lesson on Spark Plugs

[Skully4]

Hey there people

Well I wanted to post a pic of the awful old Bosch plug I took out of my Avay today but not sure how to do this. NEVER use plugs with screw on tops I have been working on cars for over 20 years as needed and never thought anything about this until today...

I had read somewhere here at TN that Bosch was a bad plug etc.
I have had my avalon for 4 almost 5 years now and I made the mistake of
trusting Bosch 2 years ago on using their product. Rebates are truly for suckers wink ...

So I installed the Boschs plugs in 2008. Recently I have had the 402 code.
We all know that is for EGR flow etc. I took care if clearing it and used seafoam in the pcv vacuum line and new pcv etc. Seafoam in oil before change and then again in the gas tank.

The code never came back on for over 500 miles. Then two days ago the CEL came on and another 402 code. I cleared it and again used seafoam in pcv vacuum line. The agenda of new plugs since reading about the awful Bosch plugshad been in my mind and I decided 2 years and it was a good time to see what else was out there NGK is pretty much the top of the line for many vehicles not to mention they are from all I have heard FANTASTIC.

3452's is the short part number at Orielys about $59.00 so the main story :

As I removed the far right front plug on drivers side the plug came out an the top was at an angle. I know I made sure to snug all this up prior to install. Now this is my thoughts on the EGR and 402 code being triggered...

Since the plug was not set right it was not arcing correctly there was oil on actually the plug next to this pne and so i am of the opinion that this loose top of the plug caused the egr code to come on. the car had to have been hurting from this shitty plug event.

In anycase i am going to go clean up and take the car for a drive and see.

The plugs that were in there were fince and of course tinkering just cause is NOT always the right way...another lesson for me. I am glad I read the post about the Bosch plug wish I could remember who to thnak them as I am sure this plug left the way it was would have surely caused me to have severe egine trouble somewhere down the road as seen by the CEL coming on and the 402 code..

so THANKS TO EACH ONE OF YOU every thought you write about helps us and I for one am very thankful for this toyota nation forum.

Have a refreshing Auntumn weekend

[skynet1988]

Made the same mistake with the Bosch plugs. Never again. I was told that the Bosch aftermarket stuff is crap whereas OEM Bosch is good

[TedL]

I don't believe that Bosch, or any other manufacturer, has two different production lines/processes/materials for the same product part #, sending one to manufacturer and the other to aftermarket. They may have "good-better-best" differentiation, with differing part numbers. The extensive plug listings (Rockauto will show 30 or more, starting at 99 cents) that pop up when you check an application should be a red flag that they're recommending almost anything in their product line that will screw into the hole--regardless of engine manufacturer's specs.

While I am quite happy using SuperTech oil and ATF, when it comes to plugs, I defer to Toyota engineers and buy the NGK or Denso # Toyota specs. For a total of $30/$45 (4 or 6), I'm good for 5 years+/-. Oh, and genuine red/pink coolant. Radiators are easy to change. I don't want to be changing heater cores/head gaskets. It's the one fluid Toyota doesn't spec a generic (on vehicles I have). Adds credibility in my evaluation.