cmpcpro

Sounds great! Why would the ecu need to be reset if the sensor is giving live data? Just curious.. how exactly does the tb elbow come off again? I though someone told me it just twisted? I assume I need to take the air box covers off first? Thanks! If I remember right my mechanic mentioned something about an air temp or air barometer sensor or something that was suspect.

Redwood415

my car does that warm up stumble when idling, seem like it happens when mixture starts to lean out slightly after cold start enrichment goes away. This would make sense since that air temp sensor directly relates to control unit determined mixture curve. For the money you cant really go wrong. I will replace just to eliminate the idling stumbles, I don't expect to achieve any more seat of the pants power.

MACEDON

Ok so I replaced it without even seeing Principles post, and I cleaned the throttle body. Sneaky ecu reset and I took off.

The car I absolutely changed, can't even describe it. Idk if it was the trottke body cleaning or the sensor but hollyyyy shhhhiiiitttttt. Wow.

MACEDON

Can you do me a favor and replace it then test the car separate from cleaning your TB then report?

I wanna see if the sensor makes a difference, or if it was just the TB cleaning, or both.

I cleaned the tb and replaced the sensor (not hard to do, break the little legs then pull it out with pliers careully, then remove the cable last) new one slides in (remember which way the direction is, the little ridge for the cable should be facing the back of the car) and did a sneaky ecu reset.

I want you to isolate and test if you have the time to see if the sensor change is actually beneficial. OP's was bad so it made a difference.

cmpcpro

That's great! I doubt the TB cleaning will do anything other than smoother idle as when on the throttle the butterfly is opened but I will try it without cleaning it. I'm fairly sure it's the sensor though.. I am excited to do it now!

principledchiro

ECU operating parameters are modified and stored according to sensor input.

principledchiro

The AIT sensor is a thermistor placed in a hostile environment, thus it degrades. When it begins to fail, its resistance increases...to the point of complete short, at which time the ECU switches to Limp Mode program...just enough throttle to go through the gears.

cmpcpro

So does that mean an ECU reset does anything?

elf

My car has 121k miles on it with probably the original Air Intake Temp sensor. I wonder if I should just go ahead and replace it since I added quite a few bolt ons recently. I've been monitor my AIT with DashCommand app on my iPhone using a obd2 wifi adapter. I'm not sure how much I trust an app on my phone to give live accurate readings vs https://tinyurl.com/ya3mwuo6 I don't mean to get off topic but I am replacing my coil packs with new ones tomorrow. My engine seems to misfire under heavy load. Spark plugs are brand new too. Hope this will resolve my engine misfiring issue.

MACEDON

Yes, absolutely replace it, I think it will help you pinpoint what's wrong.

Don't forget to clean your tb too. I felt like my engine had a tiny misfire, I ran 2 bottles of seafoam through the tank and it cleaned up its operation. TB clean and IAT sensor replace and this car feels like brand new now.

cmpcpro

Did you unscrew the air box lids and then did the rubber boot on the TB just rotate out? Thanks

MACEDON

https://mbworld.org/forums/w211-amg/...1-e55-amg.html

I made a write up for anyone stumbling upon this

Definitely the most effective repair I've done on my car.

cmpcpro

I replaced my sensor but didn't touch the ECU.. the first drive I didn't feel anything but then this morning with the second drive I definitely noticed a nice increase in power! My sensor was original with a silver AMG sticker on it. The tip looked bent from heat and the little wires looked thin or bent in one spot like it was getting close to going all the way through.

elf

would you mind snapping a picture and uploading it if you haven't already tossed it lol.

PJmak

would a c55 have this sensor or just the supercharged models?

MACEDON

Good question... I would imagine they do because it's not an AMG specific model.

PJmak

I heard on our cars its integrated into the MAF but not 100%

If someone can confirm it would be great

MACEDON

Yeah yours looks a bit different, I googled c55 air temp sensor

05-E55

How does doing the ECU reset affect an an aftermarket tune?

PieRat

It doesn't. Sneaky ecu reset just clears the cars learning adaptions. For example it resets your transmission adaptions so if your wifes been in the car driving like nanny itll shift slower trying to provide comfort. To get shifts back to aggressive you either need to drive aggressively for awhile or do sneaky reset

ATLVR6

Question, does a faulty temp sensor read hotter, or cooler? Based on the comments, I assume hotter, but does anyone know for sure?

CharlyE500

Are you guys talking about CPS ? crank position sensor or other temperature sensor ?

PieRat

My guess is hotter. You'd rather be throttling the engine performance based on an increase in resistance rather than upping performance with a false cold air rating.

I just replaced mine, had the battery unplugged during replacement. Put it all back together and started her up. Initial impressions, smoother acceleration and engine operation. Smoother idle. Could not comment on an HP gain or performance gain but on a side note another cls wearing Brabus and dressed in matte black pulled up next to me for a little race. I had a bit of ****ty start with wheel spin so he was pulling away a little until I got traction then I slingshotted past him. He raged out and pulled off into a side street..hehe

Toadster

cheap fix

Mercedes (1993+ models) Temperature Sensor at Intake Manifold 2 Pin $12






IAT sensor

PieRat

Did my map sensor. Feel like it made a big difference (more than iat). Although to be fair I did replace my kleemann which had almost cracked a weld in half just after the collector at the same time so...