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Hey guys, just recently bought my first s4 a 2001 black s4 six speed 146k with stage 2 giac, xs power turboback exhaust, and spec stage 2 clutch. Let me state I have searched high and low but cannot find any solutions for my problem. when I got the car it ran good but bogged once and a while at around 4k usually in higher gears, normally would run perfect! It idled a little rough and still bogged/misfired at 4k so I changed out the plugs to new ngk bkr7e and it seemed to make it idle better and give smoother power delivery but today when driving i went WOT and it bogged way down every time id hit 4k no matter what gear, this time the difference is no flashing cel and just sounds like its getting no boost. I tried gapping them smaller and pulling the green springs out of the 007 forge and putting in the yellow ones but to no success. I got the car scanned a day ago and got 3 codes. P0300 Random/Multiple cylinder misfire,P1113 H02S 1 Bank 1 heater resistance too high, same thing for bank 2. I constantly have a cel on, though i was under the idea that that was from the stage 2 and new exhaust, all mods are less than 2000 miles old. Any help would be greatly appreciated as this has been my dream car since I was twelve and am so eager to get it working great!
Hey guys, just recently bought my first s4 a 2001 black s4 six speed 146k with stage 2 giac, xs power turboback exhaust, and spec stage 2 clutch. Let me state I have searched high and low but cannot find any solutions for my problem. when I got the car it ran good but bogged once and a while at around 4k usually in higher gears, normally would run perfect! It idled a little rough and still bogged/misfired at 4k so I changed out the plugs to new ngk bkr7e and it seemed to make it idle better and give smoother power delivery but today when driving i went WOT and it bogged way down every time id hit 4k no matter what gear, this time the difference is no flashing cel and just sounds like its getting no boost. I tried gapping them smaller and pulling the green springs out of the 007 forge and putting in the yellow ones but to no success. I got the car scanned a day ago and got 3 codes. P0300 Random/Multiple cylinder misfire,P1113 H02S 1 Bank 1 heater resistance too high, same thing for bank 2. I constantly have a cel on, though i was under the idea that that was from the stage 2 and new exhaust, all mods are less than 2000 miles old. Any help would be greatly appreciated as this has been my dream car since I was twelve and am so eager to get it working great!
Start with unplugging the battey and let it sit overnight, its just to drain the last little bit of power out of the capacitors in the ECU, That will reset the computer, and turn off the check engine light.
It sounds like your S4 is over boosting for some reason, I would check the N75 valve first, it needs to be connect for the car to sense how much boost is actually being achieved. Do not bypass the N75 with a manual boost controller, the turbos will spool up too quickly (depending on size, like small K03 & K04 turbos) and building high boost too soon so by the time you hit 3-4k rpm the waste gate has to open and dump all the boost out, and it falls flat on its face!
Start with unplugging the battey and let it sit overnight, its just to drain the last little bit of power out of the capacitors in the ECU, That will reset the computer, and turn off the check engine light.
It sounds like your S4 is over boosting for some reason, I would check the N75 valve first, it needs to be connect for the car to sense how much boost is actually being achieved. Do not bypass the N75 with a manual boost controller, the turbos will spool up too quickly (depending on size, like small K03 & K04 turbos) and building high boost too soon so by the time you hit 3-4k rpm the waste gate has to open and dump all the boost out, and it falls flat on its face!
I hope I've been helpful...
I appreciate your input! I just got the exhaust all welded up today, and it did change how it behaved, boosts pretty normal through first gear, but others it still bogs. People have told me that my front o2 sensors are bad and I'm going to change those out later this week to see if it makes a difference. Im very new to this car, but in regards to clearing codes that way, i've read that it can screw up my tune and or somehow delete it from my car, I don't know if thats true or not, just cautious. Also since I'm new to these cars, and new to turbos, what and where is the N75 valve? I did a boost leak test the other day and found one small hose that had come undone but that just connects to the intake tube.
I appreciate your input! I just got the exhaust all welded up today, and it did change how it behaved, boosts pretty normal through first gear, but others it still bogs. People have told me that my front o2 sensors are bad and I'm going to change those out later this week to see if it makes a difference. Im very new to this car, but in regards to clearing codes that way, i've read that it can screw up my tune and or somehow delete it from my car, I don't know if thats true or not, just cautious. Also since I'm new to these cars, and new to turbos, what and where is the N75 valve? I did a boost leak test the other day and found one small hose that had come undone but that just connects to the intake tube.
Resetting your ECU won't make your settings go back to stock, it's just to reset your check engine light.
It boosts good through first gear because 1st. gear is too short and doesn't produce enough flow/volume in the short amount of time to cause the turbos to over boost.
Resetting your ECU won't make your settings go back to stock, it's just to reset your check engine light.
It boosts good through first gear because 1st. gear is too short and doesn't produce enough flow/volume in the short amount of time to cause the turbos to over boost.
How would I go about testing if its the n75 valve?
How would I go about testing if its the n75 valve?
Check to see if the N75 is plugged in and lines are routed property. The N75 valve should make a ticking noise when idling, if you listen closely under the hood near the unit. The N75 valve is just an electronic solenoid boost valve that pulses up and down at a different speeds to control boost levels. Its on the line that connects the turbo intake housing and the waste gate.
Check to see if the N75 is plugged in and lines are routed property. The N75 valve should make a ticking noise when idling, if you listen closely under the hood near the unit. The N75 valve is just an electronic solenoid boost valve that pulses up and down at a different speeds to control boost levels. Its on the line that connects the turbo intake housing and the waste gate.
checked today and Im pretty sure it was making the ticking noise, its kind of hard to tell with all the other noises going on.
03-25-2016, 07:43 PM
no boost/bogging at 4k in all gears
