bbearden

I have a question concerning a performance upgrade I recently purchased but have yet to install. The purchase is a resistor with instructions on making the modification. The intake air temp sensor is unplugged and the resistor is then plugged into the plug, connecting both sides of the sensor. The sensor is then not plugged back in. What this essentially does is it fools the ECU into thinking there is colder air coming into the intake. The ECU then advances the timing (up from the factory setting of 6 degrees of retard). A net power increase of up to 20 HP is claimed, although intuition tells me an increase of 10 HP is about right.
My concerns are that this could result in some sort of electrical problem or that in doing so, on hot days my car might run excessively rich and foul out the plugs. Its an easy modification and am curious if anyone has heard anything about it, good or bad. Also, there were no pictures with the instructions specific to the CLK 430. Is the intake air temp sensor (IAT) located right at the throttle body? Just want to clarify its not some sort of throttle position sensor.

Sorry so damn long!

Blake

Zeppelin

Unplugging the sensor and placing the resistor across the plug is not the way to do it. If you are going to do it, you should cut one of the wires to the IAT sensor and install the resistor in the wire. You may need a different resistor value however. This will place the resistor in series with the IAT and allow for air temp changes to still be seen by the ECU. They will just be offset to the colder side.

Personally I would not do it. The ECU may learn its way around the resistor and go back to stock or it may throw a code on certain days. Hope you only paid 10 cents for that 10 cent resistor.

bbearden

Thanks Zeppelin! I was sure that if I left the IAT unplugged it would throw a code. As for the price, I paid a few bucks for the instructions but I knew what I was getting so I didn't get suckered. Thanks for the advice!

Blake