ok,here i go,

My friend bought a act street clutch with heavy duty pressure plate and a competition clutch 12lb flywheel is was compatiable from what research i idd for is 06 scion tc,with 65k miles on it,ok we installed it this weekened,took the all day,

Now after we were done,keep in mind we took off part of his injen cai tubingmfrom the throttle body to the fender,we discoonected the MAF plug but didnt take the actually sensor out of the tubing,we laid it on a towel so it would get scratch on the cement,long story short,after we were done,with the clutch,we made sure we can get into all the gears with the off,it was good,then we connected the battery back up and all the connections,we started up the car,it ran like crap,the idle was all over the place,usually takes 5 mins for the ecu to reajust itself,it never did,it threw a code with the CEL on,we scanned the code,came up with a P0103 code,which said to be the maf sensor low input,we made sure it was securely connected along with everything else,car was running rich,so we cleaned al the connections along with the maf sensor with the maf sensor cleaner,thinking some dirt might of gotten on the sensor,so after that was done,we reseted the ecu again,the car ran alot better,cleared the code,did the like 2 times,cause the first time we just cleared the code,it came right back up,thats what made us clean it,short story we got the cel off,no codes,but now when you accerlerate,the car jumps back and fourth bad,every time i drive the car,idles fine,the maf sensor gave us problems from the begining,i cleaned it,seems alot better,but dont know what going on,hope u gies understand my story

 

What all is done to the car mod wise? Is it stock except CAI and the new clutch? Any other codes?

Also follow the wiring from the maf and make sure it didnt get pinched anywhere.

 

Oh and did you make sure to hook up the crankcase vent hose from the intake pipe to the crankcase vent? If not that would cause a massive vacuum leak, and the car to run like crap.

 

not much was done,basic mods,exhaust,short shifter,injen cai,i doubled check that big black hose that goes to the intake,made sure that was on tight,we didnt really disconnect much,besides,the cai,we took out the starter,battery,keep in mine,the maf gave us the problem in the first place,threw a p0103 code,i tried to turn it off to see what happens,came right back on instantly,cause the car ran like crap idle wouldnt go back to normal,we shut down the car,i took out the maf sensor cleaned all connections,made sure it was tightly on the piping and all that stuff,we turn the car back on it ran alot better,but i reseted the ecu just in case,then it idle low for a few mintues unlike the first time and went back to stock idle with in 5 mins,cel went off by itself,still had codes,p102-p103,so i cleared them,we try to drive car,back jumps back and fourth very violently,almost like it cant get air,or the timimg isnt correct,i read that sometimes the ecu goes into a fail-safe mode thing,someone said try a different maf sensor

 

Yea could be a bad maf. Does it free rev ok? (Does the issue only occur under load) Are you able to monitor ST/LT Fuel trims with the scanner you have? If so, how do they look? Also what is your intake air temp? (If your scanner is able to monitor this PID)

 

yea it revs fine,disengages and engages fine,but as soon as you but a load on it,thats when it happens almost like its choking,enough to rock you back and fourth in the seat rough ,i have the scangauge hooked up thats how i read the codes,ill check out the PID tommrow,what should it be...

 

IAT should be within 20* of ambient, lt and st fuel trims should be as close to 0 as possible. When does it rock, when you first engage the clutch or at any rpm?

 

ill check out those number tommrow...as soon as he put a load on the car or accelerates it rocks back and fourth pretty bad havent droven the car since maybe up and down the block no higher then 2500 rpms,im gonna recheck everything again,i have another buddie that gonna let me try his maf sensor to see if thats the issue before i buy a new one,hopefully thats the issue,

 

just and update,we replace the maf sensor,and that fix that issue,i noticed that if we doing 40 mph,i here metal rattles,we torqued everything to specs,what could be loose