Need some help. codes

[Monterusto]

This morning i decided to re run my codes after a 20 min drive.
first i hosed down the maf filaments with some electric parts cleaner.
then reset idle sdpatt proceedure
ran koeo-11/66,91 ,erased codes
then ran koer. funny i turned the car on to run and immediately got 98, 25 without the id first.
Did it again koer-91, 25
then cylinder balance test 4, 6 came up
can some one give me some info and assistance!

 

[Monterusto]

im guessing it may be an injector problem. are cly 4 and 6 on the same o2sensor as the 91 code. i will check the injectors for their tick (using a long screwdriver. by the way since i got the car the injectors im assuming, tick really loud.

 

[Monterusto]

injectors 123 had nice tick. i could be paranoid
but 4 sounded different( a little harder louder tick) 5 was ok and 6 i didnt trust the reading it was very tight to get to and the tick was echoed. so i looked at the plugs 4 and 5 were fairly light, 6 was dark with a small cake of carbon on the outer ring of the plug but not all the way around.
i only checked 2 on the other bank and it looked like 4 and 5.
i am using bosh platinum (1's)plugs which have about 8000 mi on them. i dont know the terminology to describe the plug parts so ill describe it the best that i can. on the cone part of 456 there is no visible electrode only a hole. plug 2 had one, probably 1 and 3 also. i know each bank wears plugs differently, explaining what happened to the plugs.
can this be directly related to my problem. Could those plugs have not been sparking properly? Would that cause a 91 code? im a little confused?

 

[masho95]

Monterusto:
im guessing it may be an injector problem. are cly 4 and 6 on the same o2sensor as the 91 code. i will check the injectors for their tick (using a long screwdriver. by the way since i got the car the injectors im assuming, tick really loud.

Yes cylinder 4 and 6 are on the same side as your 91 code (front O2 sensor lean). This is refering to the front of the engine as you look at the car standing in front of it. And for the other post after, if 4,5, and 6 spark plugs (the closest one to the front of the car) have no electrode only a hole, that is definitely an issue. I would start by chagine out those front plugs and see what happens. They are very simple to change. As for the 91 code you should be getting a CE light when running... are you?

 

[Monterusto]

i swapped the bosh plugs with motorctaft and noticed a much better response in performance. i drove the car on the highway for about 100 mi. and the cel came on and went off a couple times.

 

[masho95]

If the CEL light is coming on and off on the highway, it's usually a bad O2 sensor causing that. You might want to start thinking about changing them, specifically the front one.

 

[SHO_Driver]

Monterusto:
i swapped the bosh plugs with motorctaft and noticed a much better response in performance. i drove the car on the highway for about 100 mi. and the cel came on and went off a couple times.

I'm also running the Bosch's (put in before I knew about this wonderful forum) and after only 15K miles I noticed pitting on the white casing around the platinum electrode. It looks like tiny pieces were eaten away. Now I've seen why Bosch doesn't belong in our beloved Yamaha.