I have a K&N Intake and a Tsudo Exhaust installed in my tC, everytime I startup the car with the intake with a replacement MAF sensor from toyota, the RPMs instead of shooting up to around 2000rpms on a cold start it, it would shoot up to 3000 back down to 2000 like a normal startup, i don't know what could be causing this, the couplings on the intake have no gaps but i do have an exhaust leak in the exhaust which i will get fixed, I know the car threw a p0101 code and p0172 from a bad MAF and it started up the same way, i just installed the MAF sensor yesterday and still starting up the same way, idk what could be causing this, maybe there is a leak in the coupling that i couldn't see? I'm just out of ideas...if anyone could help, it could be greatly appreciated

 

Silly ? But sounds like the ecu wasn't reset by disconnecting the battery during install.

 

Disconnect the battery and leave it for about 10 minutes to reset the fuel maps. They are probably all messed up from the old faulty sensor.

 

I disconnected the battery when installing the sensor and let it idle for 10 minutes, I just don't know if I left the battery unplugged long enough to fully reset the maps, I'll check the intake tomorrow morning to make sure everything is connected probably and leave the car unplugged for about 10-15 minutes to make sure everything is properly reset

 

i definitely disconnected the battery, maybe just didn't keep the battery disconnected long enough, maybe, i am definitely going to check the intake tomorrow and reset the battery one last time, it hasn't thrown any codes, but the higher then normal revs on a cold start is whats concerning me most

 

Even if unplugging the PCM doesn't solve your issue right away, the PCM will adapt over time. Don't sweat it man.

 

I noticed something like this when I installed my TRD intake on my 14 TC. The car would Idle around 600 which seemed a bit low to me. When the AC is on, the RPM would sway between 600 and 800 consistently every 15 secs. However, everything seem more stable now (had the intake on for a week now).

 

RPM's will rise when the A/C compressor engages to compromise for the extra effort needed to turn the compressor. Unless if you are using ebay intakes, they really wont have any adverse effects on idle

 

so this morning i took apart the intake, no leaks or anything, then i realized the i installed the heat shield, well wrong, it uses three bolts and the way i put on the third was wrong, i re-did the intake this morning, it looks exactly like it does in the pictures, the tubing it completely away and not close to the motor, it started up a lot better this morning and idled a lot better right after i put plugged the negative terminal back on, hopefully that did the job, plus i noticed a dent on the tubing of the intake by the throttle body end, but with the coupling and the heat shield holding it in place, that shouldn't be a problem, fingers crossed!

 

Let us know the the cerdict