The_Phantom

I have a 2003 C4S that wasn't idling smoothly. Last week I cleaned my MAF with CRC Electronics Cleaner which seemed to help slightly. Since the idle still wasn't as it should be, I thought I would clean the throttle body and I ordered the CRC MAF Cleaner to clean the MAF again with the special MAF cleaner. (By the way, the CRC MAF Cleaner claims that by using it, most cars gain 4-10 horsepower at the wheels. The bottle said that they had a chassis dyno set up and tested a series of cars and those were the typical results.)

I had to remove the air filter housing and MAF sensor to get to the throttle body. My car has about 19k miles and, although you can't see it from the pictures, the throttle body was surprisingly dirty. Inspired by the Intake Snake Throttle Body cleaning tool (http://www.run-rite.com/industry/pro...d.htm#ORDERING) which I read about in this article about cleaning throttle bodies posted by a fellow Rennlister (http://www.popularmechanics.com/auto...t/1272341.html), but didn't want to order, I taped a rag to a long screwdriver and made my own (poor man's) intake snake. Then I sprayed the inside of the throttle body with the CRC intake cleaner in the picture below. I also sprayed the rag attached to the screwdriver and wiped out the inside of the throttle body removing quite a bit of the dirt. And I also sprayed the MAF with the special MAF cleaner and then replaced the air filter housing.

I shouldn't have waited so long to clean it, I guess, because I had to use so much cleaner, that when the car started it ran rough (which usually happens when intake cleaner is sprayed in the throttle body) but also caused the check engine light to come on. This is the first time the CEL came on in my car. Did someone say that those codes have to be cleared at the dealership? (If so, no big deal, I'm taking the car next week to get a piece of plastic I broke fixed and they can do it then). After the about two minutes of rough idling everything smoothed out and it is now better than it was before but still not like new (might need some fuel injection cleaner too...?)

Dale Gribble

looking good man.
funny u should mention this, i was actually going to do it next week after i send my car 2 the paint shop.
I've been having a slightly erratic idle that was buggin the hell outta me.

LVDell

That is one great makeshift tool!

Nicolaasdb

does cleaner your air intake really work??? and how the MAF cleaning??

Anybody knows if cleaning these 2 is looking for trouble (CEL light coming on, etc)

nycebo

Cleaning those two should not be cause for CEL, but if you handle the MAF improperly or don't let the cleaner evaporate long enough, it could conceivably do so. Just ask Fishman. I think it's a great idea to clean the MAF and the intake about once a year (indeed, I'm planning to do so this weekend).

Fish, great write-up. Your intake looks very clean now. I'm sure your CEL is just because you moved the MAF sensor a bit and nothing serious at all. As to your underlying problem, I'd try one last thing before bringing in the pros: wait until your tank is almost empty and then put in some Techron. See if that helps.

Tim Wasmer

Duct tape rules the world Dell!

The_Phantom

By the way, I should also tell everyone that the instructions on the CRC Intake Cleaner say to use when the engine is hot. Since I already removed the air filter housing, etc. before reading the instructions I sprayed it into a cold engine. I can't imagine that would make a big difference, but next time, I'll make sure to drive the car first.

The_Phantom

My thought was that because the engine was running rough for about two minutes as the intake cleaner went through the system, that that was why the CEL came on.

I know there isn't anything wrong with the car, since it is running better than it was before the cleaning, but someone told me that (and if this is wrong then please tell me) something like a CEL can cause the engine to detune itself for safety and needs to be cleared at the dealership. That seems strange to me, is that true or is there a grain of truth to it?

Dale Gribble

^ i don't believe that this is the case ALWAYS. if the cel was triggered by something sevear enough, then the car may go into limp mode, otherwise it will just be a warning light. If you have an OBDII scanner you can read out the fault code and if u deem it to be caused by something unimportant, you can clear it yourself.

nycebo

You would feel it if it went into limp mode. I had CELs all the time on my Boxster S (that damn O2 sensor was ultimately the problem and had to be replaced.....and the CEL still came back on) and never noticed a thing.

The_Phantom

Should I still ask the dealer to clear the code since the car is going to be there anyway (even if it didn't go into limp mode)?

nycebo

If you can't get access to an ODB reader, then you should first have the dealer tell you why the code tripped and what they codes are (so you can look it up yourself too). Then they can see what 'may' need to be done.

FlashingBlade

What's the difference between Air Intake cleaner and just plain old carb cleaner?

How do you open the throttle if it's an e-throttle?

1999Porsche911

Nothing, except the price. Don't get sucked into paying more for the label. Same goes for the so called MAF cleaner.

jslindst

Guys,

I would recommend against using carb cleaner. You should use a product that is specifically for cleaning throttle bodies because most throttle body have a coating inside to slowdown the build-up of deposits inside. Most(not all) carb cleaners will remove the coating leading causing the deposits to comeback quicker. IMO its not worth saving $1 or $2 to risk it. Its also good to take your car on a road trip(30 miles or so) to ensure that all the cleaner is sucked through the throttle body, intake manifold passages and into the combustion chambers. Some of these cleaners(even throttle body cleaners) can eat through gaskets in the intake system if they soak into them for too long. Just my opinion, I could be wrong.

Jeff