Re: Report on throttle body.
I'll probably "stir the pot" by saying this, but -
Do you have a German engine in it?
Was that engine designed around Bosch plugs?
Bosch plugs are "fits-alls" at best. Unless you are really
lucky, the heat range will be off, and the indexing will be
wrong too. Ask your wife how she likes "one size fits all"
Bosch uses very few application numbers compared to OEM.
"If it fits in the hole, use it" is their credo.
Parts houses promote them because they cost next to nothing
but they get regular retail.
You can't get around the wrong heat range, but you can the
Pull the head off, install the original plugs that the engine
was designed around, torque to spec.
Mark the head on the outside by the plug hole as to where
the ground electrode is pointing.
Now, when installing knock-off plugs, ie., yellow, blue, pink,
platinum, knurled, split, multi, "magic," etc plugs you can
at least position them right.
The ground electrode creates a "shadow" in the chamber,
lowering HP, lowering mileage, and raising emissions if
It can make a difference as much as 20-30 HP on some engines.