JLA117

So I changed my knock sensor. I have the old one and it's all cracked. It says on it unisia jecs Japan and the rest is cracked off. Is that the original? If so its lasted 201,000 miles. Anyway, I needed that replaced. As my previous post said that my car was turning off at red lights and studdering when I was driving 40 mph and they said it was the MAF. The SES Light is on. I could swear my MAF is working since I unplugged it once and car wouldn't idle past 2000 rpm when driving or on park. When I reconnected, it was ok. Well since I changed the knock sensor by squeezing my hand, it was maybe a possibility that it was causing MAF to fail. The car hasn't studdered and the performance is better than before but there's a rough idle now. On drive it idles at 600 then goes to 500 rpm, is that correct settings? It was the same before but it wasn't rough and the lowest it idles was 500 on drive. Is it still the MAF? The car idled like a new car even though it has 200k. And now I can hear a whistling sound coming from gas tank. Fuel pump? And last thing, before all this happen, on take off the gas pedal is kind of stuck and you have to use a little bit force but that makes car jump on take off and you hear a slam of some kind.it makes you think it's the transmission but the pedal sticks up. I have to always let go of brakes for like 2 seconds before accelerating if not it sticks the gas pedal.

JLA117

Update. I diagnosed the check engine light by counting pulses. There were 13 short pulses and 2 fast ones. Code is 1302 and got MAP/BARO SW Solenoid/Valve

theWalkinator

Here is MAP/BARO solenoid location, there are 1 hose goes (from manifold) in and two smaller hoses come out (air box and MAP sensor), check if any of those hoses fell out, cracked, you might accidentally damaged those hoses when you were trying to replace KS, if all hoses are fine, unplug the connector, supply 12V to the solenoid, if you hear a click, then the solenoid is fine, trace the hoses to see if cracked or loose on the other ends, also measure the voltage on the connector two pins when key is in on position:

JLA117

Switch and connector are both working when I performed the test. Connector gave me a little over 12 volts. The switch it self sparked and ticked. I'll look again for any loose hoses. There's just to many sensors and stuff in this car that get in the way maybe I over looked.

sonnyramirezz

i was having a rough idle onmy car and i clean the idle air control valve it worth a shot good luck

theWalkinator

^+1. There is one small hose from MAP solenoid connects to IACV IIRC, yeah, take air box and conduit out, clean the throttle body with carb cleaner, take IACV out and also clean it good with carb cleaner, while you are at there, you may also take a peek at top of the EGR tube from IACV port to see if it has a lot of carb buildup, it may get clogged which is a common problem on 4th gen Max, you might want to spray carb cleaner into EGR tube to get it cleaned, if clogged really bad, the only option is to take out EGR tube, there are few good DIY threads on cleaning EGR tube.

JLA117

I rechecked all hoses and stuff. I don't know what it could possibly be. Absolute pressure sensor that connects to it is also working too. Got another MAF on the way. 40$