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View Full Version : SR20det Red/Blacktop Knock Sensor Question

dorkidori_s13
12-21-2013, 07:25 PM
My SR has been getting worse and worse lately as far as this little gremlin Ive had running around causing problems. Its narrowed down to either 1 of two things that I can think of...

1) BAD KNOCK SENSOR

2) BAD MAFS

The bad knock sensor is a definite as I hooked up the car up to Nistune when I put a new TPS in last week so I could properly set the IACV, TPS and Throttle Set Screw (to enable closed throttle flag). When Nistune checked my ECU, it found code 34 which is Knock Sensor Fail. I have a new knock sensor on the way and it will be here Monday.

In the mean time, I believe Code 34 can also relate to MAFS issues as well (my MAFS has never given me issues, its cleaned every month and I run a K&N Air Filter). The symptoms of the motor right now are CRAP gas millage and REALLY bad hesitation in accelerating at mid to full throttle between 1500-3400 RPMs (car pulls fine when in boost). There are no boost leaks, everything works fine in the engine.

So can anyone confirm to me what I already think I know. The car is in limp mode at the moment due to a faulty knock sensor (which Ive read causes all the symptoms I currently have). Has anyone ever had their knock sensor go out on them and pull code 34 from the ECU?
dorkidori_s13
12-21-2013, 08:37 PM
Ive done tons of searching in the subject over the last few weeks. I thought it would just be nice to engage others in conversation about the problem.
ultimateirving
12-21-2013, 09:14 PM
Can't you turn off the knock sensor with nistune? I just did the resistor bypass and haven't had a problem since. But I plan to turn it off once I get some proper software
dorkidori_s13
12-22-2013, 12:10 AM
Can't you turn off the knock sensor with nistune? I just did the resistor bypass and haven't had a problem since. But I plan to turn it off once I get some proper software

turning off the knock sensor on the factory ECU is a bad idea (even on a full tune its not a great idea to do). the knock sensor actually does retard or advance timing to help with fuel consumption or starvation. if you run a PowerFC, it helps you keep track of whats going on with your motor under harsher driving conditions.
OnTheChip
12-22-2013, 06:53 AM
Code 34 is strictly for the knock sensor and has no relationship to the MAF. If you have code 34, the ECU will pull a constant 5ยบ below 5000rpm.

Sounds like the MAF may be dirty.