I installed a 5/16" Motordyne plenum spacer, 06 Airbox, reinstalled my Z tube, and replaced the stock y-pipe with a stainless steel one on Saturday.

It ran great all day Saturday and Sunday, but today... it has no power over say 3500rpm, I can floor it and it'll spin but then it just slowly increases in speed, in automatic mode it wont even hit passing gear, and even if I switch to tapshift, in 3rd it just wont go, it's almost like it's not getting enough air? possible throttle body issue even though there are no codes? i tried the ecu reset, idle air, and throttle position learning to get those out of the way as well......

 

Sounds like limp mode to me...check your maf sensor is clean and tightened down properly

 

try ecu reset

 

Check is a hose clamp came loose or something unplugged itself. CEL?

 

Make sure your MAF sensor is facing the right way.

 

no codes.. did the ECU reset, going to check all the hoses and MAF direction in a few...

 

MAF is clean, screws are tight, and facing the correct direction. ALl Hose clamps are on, no vacuum lines are loose or crimped, right now trying the ECU reset again... (unhooking battery, pressing brake pedal and letting sit for a while)..... (I did take off the Z-Tube just to see if after i started it the butterfly would open all the way when the gas pedal was floored, obviously it ran like crap without the tube and MAF still plugged in, but the butterfly opened all the way)

 

ok.. still no go, CEL is on... codes are p1020 and p1130......

 

P1130
Swirl Control Valve Control Solenoid Valve

 

sounds like the y-pipe and intake might have triggered it.

 

I read that swirl contorl valve can get clogged with carbon... possibly when I added the plenum spacer and changed the intake boxes maybe some mades it's way and built up inside?

not sure how the Y-pipe would effect that? you saying maybe just the increase in flow screwed it?

 

some please enlighten me on what,where a swirl control valve is

 

has something to do with a more efficient mixing of air and fuel at different speeds... BUT.. after resetting the ecu yet again and using an actual scan tool, it's O2 Sensor, Bank 1, Sensor 2...

 

Replaced 02 sensor.. it's better, but still no go when you put it down.. doesn't even matter if I switch to tapshift say into 3rd, it still acts and feels like it's choking....

 

trying a long ecu reset (unhooked the battery) and tonight going to take everything off and inspect for anything that might have been leaking or loose...

 

unreal...... sit down for this one...

The "bogging" and "hesitation" i was feeling was caused by....... my LED "bulbs" I put in the tail lights to replace the normal bulbs (there are 64 LEDs on each one, half would light up for parking lights, other half would light up when you apply the brake.) YEP.

In some cars, the LED bulbs will cause brake warning lights or a CEL to come on becuase of the difference in OHMs from regular bulbs.. well.. in our cars (at least a 2004 350z, so I'd assume 03 - 05) it causes the electronic brake distribution system to kick in above 2500 RPM until about 4500 RPM, in other words, my car was actually braking.... w...t...f.

I Replaced the LEDs with brand new regular bulbs.. car runs like a champ. Maybe a Mod/Admin could post something somewhere so that this is a known issue....

 

well if you do a search for it you'll find tons of people that changed there 03 tails with 06 tails and had the same prob. now if only there was a fix.

 

there is, on ebay they sell a setup you wire in-line that changes the OHM output (I assume it's just a set of resistors).. if you do a search on ebay for LED bulb OHM or fix they'll come up...

 

Another fix is to leave the GD taillights alone....so many times in the name of aesthetics or performance, the car, or any car just starts going to $hit.....ask all the FI guys how reliable their cars are.

 

Very reliable.