changed plugs and oil, have some questions.

[jmd2914]

I swapped out my bosch plats for some correctly gapped autolites ( .054) and i changed my oil from a 10-40 to a 10-30. the car seems a bit faster not sure why but i think it backfired once or twice when i downshifted on the highway. i couldnt get it do it again after that though, is this normal? and there is some stuff on my x pipe, looks like corosion from the o2 sensor to the cat. what is this?? is it bad? thanks guys. :SNSign:

 

[daddystang]

How old is your x-pipe? May be just normal wear and tear. Was it a backfire, or just sound like rumble out the tail pipes. Mine makes a rumble sound when I down shift sometimes, and I've heard others do the same thing. Good luck..

 

[jmd2914]

xpipe is a acouple years old and i downshifted kinda hard so it might have just been a loud rumble, i run race bullets dumped so sometimes its hard to tell

 

[310stanger]

the car feels faster cause autolites are a good plug and bosch sucks. i get cars all the time at work that misfire and they have bosch plugs. they are overpriced pieces of crap.

 

[HISSIN50]

I'd chalk up the afterfire to having such an unmuffled exhaust. The cats and more sedate mufflers normally knock down farts that are otherwise heard during transient maneuvers (like a down shift).

Good luck.

 

[jmd2914]

it does feel faster, but when im in neutral and i rev the car to like 1800 and let it down it sounds almost like its backfiring but not loud, almost like a puff opposed to the loud crack of a backfire, if that makes sense.