So i been posting about ebay coils sparkplugs and random misfires...well i put all original coils back on and swapped out the bad coil for the oem denso swapped out the new oem denso plugs with the ngks cleaned maf sensor and intake. Well FML im still getting random misfires at full throttle. When i pulled the denso plug pass side near firewall it was black all others kinda white these new plugs had less than 50 miles on them...whats going on with this car please help..i sold my 08 m3 cuz it had 115k miles and was getting nervous about things starting to fail so i bought a 2011 is f with 120k on it cuz figured screw it this car will last longer. Only a couple grand outta pocket to buy car 3 years newer with pretty much same miles...now im literally gonna trade it in take a lil hit and just go back to m3, if i cant figure this out soon...figure whatever dealer i bring it to wont beat the crap outta it if they even test drive it so if anyone buys 2011 black is f on east coast, make sire u fully test drive it...please help or tell me where to take it..sorry didnt proofread nobody get on me about my grammatical errors please

 

 

Pull the codes. Misfires can be caused from a lot of things and in your event, if the plugs and coils are ok, it's probably something else. Check for vacuum leaks. Check your intake box and tube. Check the maf sensor. Keep checking down the list and see where the culprit is. It may also be a fowled o2 sensor(s).

 

if its beyond your scope, take it to a reputable shop.

 

I did get o2 sensor bank 2 on one code i pulled, and i pulled off the typoon intake cleaned everything including maf and throttle body and tightened everything up good.

 

what did the wave forms look like? and delay in signal ? voltage range?

 

I just read it on my scanner about o2 sensor..not sure what voltage etc etc...most of this is beyond me so guess ill be bringing to lexus dealer sooner than later

 

Post the codes you got. You never said previously you have a K&N intake. Are you certain all the hoses are correctly routed? Air leaks can cause all kinds of issues. Also, have you tried an injector cleaner? One black plug with only 50 miles says there is something not right with that cylinder. It's had multiple plugs and multiple coils. There's not a lot left to be problematic.

1. Did you clean the MAF with a solvent capable of removing the oil from the air filter?
2. What other mods does this car have? Headers? Midpipe? Aftermarket exhaust?
3. Did it just start doing this, or has it done it from day 1 after purchase?

Too bad you're not in Atlanta. I am sure it wouldn't take long to sort out with the right tools.

 

Bought it it was fine but decided to do plugs cuz of the mileage and they were original..car ran fine but i did feel like it was lacking a lil power thats y i did plugs...only mod is the intake..i bought the maf cleaner thats for maf and throttle body. And i ran a bottle of the eg44k everyone talks about. Intake was already on the car...also if i hit half throttle it feels like its holding back and hesitsting, seems bouncy like im hitting gas and letting go of gas. But im stsying even on the pedal.

 

Well.the plug that was black wasnt even tight at all i literally turned socket a half turn and i thought the plug socket i had was loose or something so i pulled it out and the plug was attached...needless to say that guy wont touch thid car again . Thats y i did everything myself, oh and when i go into limp mode i pull over shut car off turn it on and checking engine and traction light dissapear

 

Installing spark plugs and only guessing at torque is really bad. It's certainly bad for a plug to be loose, but it's worse for a plug to be too tight. It distorts the shell and changes the heat range characteristics. Hopefully that isn't what you are facing. Are you able to replace the blackened plug? Once carboned up, plugs rarely work well again, and high load missing is a clear indication the plug isn't firing properly under load.

 

Yes i replaced all 8 again...and i tourqued to spec 15lb

 

Starting to think something wrong with thst cylinder...more than likely ill just trade it in cuz pretty tired of dumping money into it..its leaving bad taste in my mouth...might bring to lexus monday and see what they can find

 

Not to be a wet blanket, but Lexus wants to sell you a new car.

Best best for a strange deal is an Indy that specializes in toyota or at lest imports. Tough call. I don’t trust anyone anymore. So I guess my advice is to be taken with a grain of salt.