[skidoo'sbest]

If your air filter is really dirty could it cause the car to run lean? My dealer is saying that a lot of my problem is a dirty air filter. I know it isn't that dirty because I cleaned it not that long ago(K&N) but they are saying it is causing lean engine codes. Also my absolute manifold pressure sender is bad too. I was thinking if the air is restricted (dirty filter) wouldn't it cause more of a rich code because there isn't enough air for the combustion? Any help would be appreciated so they don't try to screw me. By the way the vehicle is an 03 Chevy Trailblazer.
Thanks

 

[sledguy0405]

A dirty air filter would cause the motor to run more rich, same thing as a sled if you restrict the air flow the more fuel it will get.I would replace the air filter and the pressure senser and see what you get.

 

[skidoo'sbest]

That's what i was thinking as far as the filter was concerned. I can just clean the filter (K&N) Thanks. Anyone else have some thoughts?

 

[BAMMER]

I have heard from a number of people that the K&N cleanable filters are prone to letting more dirt in than regular paper ones? Take it for what it's worth...Can you try running the stock filter again and see if that takes care of the problem.

 

[Deadman]

K&N flows more, so it could make it lean because of the extra air??????

 

[CustomRev]

This minor thing will not adversely affect your air/fuel if the vehicle is injected. The computer will monitor the fuel in the exhaust with the O2 sensor, and adjust accordingly. A dirty air filter may result in loss of power, but not likely a lean condition. Probably another problem....
The only thing with a K+N is that they will get dirty quicker than the stock element, so frequent cleaning is needed. You can buy a recharge kit for not a lot of money.
If the vehicle is carburated, a high flow filter will cause a minor lean condition, but not enough to affect vehicle running. Years ago, we used to flip the cover on the air cleaner to open up the element (remember that, you old guys???)

Lean condition in usually EGR, Mass airflow sensor, or simply 02 sensors.

Keep the K+N, unless you want to cut down your maintenence...then put a stock Fram elelment in there.

Just my .02

Jerry

 

[05SDI]

Read some of the tuner threads...
It is said that the oil on the K&N filters mess up the O2 sensor, therefore throwing codes.
K&N's are known to be less restrictive there for more and if not corrected by more fuel could cause lean condition. (Like Deadman said)
05SDI

 

[bengelp]

It is very true that the K&N filters can cause trouble with sensors. I put one in my '96 K1500 and it set a rich mixture code EVERY time even though the readings from the scanner said everything was OK. I have also heard of other people having trouble with the oil from the filter raising hell with the MAF and MAP sensors and burning up a HEGO sensor from time to time. I talked directly to the K&N people and they are aware of these problems but they are relatively widespread problems that are more of an annoyance than a real problem. Usually the problem is from the consumer over oiling the filter, but mine caused problems right out of the box.

On the other note of bypassing dirt... I took my K&N filter out after seeing the results of a very extensive independant study of many different air filters. While it is true that the K&N filters have much superior airflow (when clean, at least) to most other filters, they also bypass the most dirt. In fact, the K&N filters actually do a better job of stopping dirt when they've been used for awhile and are dirty, but at that point the airflow drops below that of a good OEM style filter such as AC Delco or Wix.

My opinion... K&N filters are good for the race track where maximum airflow is needed and filtration isn't such a big deal. I wouldn't use them in the average daily driver.

 

[blackmxz]

I have seen the oil from the filter coat the Mass air flow sensor and cause problems. Food for thought

 

[Deadman]

MAF's are NOT cheap!

 

[skidoo'sbest]

hEY THANKS A LOT FOR ALL THE REPLYS

 

[ForceFed]

Could be bad O2 sensors, but on a hunch have you checked your injector O-ring seals?
I had a toyota PU at one time that was throwing "mixture too lean" codes and that was because the injector O-ring seals had deteriorated letting post MAS or MAF air into the combustion chamber, causing a lean condition. Also, if you are running an aftermarket air filter like a paper element filter, this will obviously let more dirt in and can cause a dirty fuel injector in which case the spray pattern will not be as effecient.
The fuel injector would then be getting the proper voltage thinking it is spraying the correct amount of fuel when infact it is not, causing a lean condition as well. Food for thought.

 

[bengelp]

Years ago, we used to flip the cover on the air cleaner to open up the element (remember that, you old guys???)

Jerry

[snapback]688248[/snapback]​

HA HA HA! Do I remember!?!?!? It made my old '78 K10 and '78 Jimmy sound like supercharged beasts! It made a hell of a lot more power than breathing through that tiny 1.5" hole in those air cleaner snorkels! It sure did raise hell when you forgot to flip 'er back over before you went out bucking snow drifts, though!

ForceFed, I must just be a rookie, but I've never seen an air filter problem cause a plugged fuel injector.

 

[ForceFed]

Years ago, we used to flip the cover on the air cleaner to open up the element (remember that, you old guys???)

Jerry

[snapback]688248[/snapback]​

HA HA HA! Do I remember!?!?!? It made my old '78 K10 and '78 Jimmy sound like supercharged beasts! It made a hell of a lot more power than breathing through that tiny 1.5" hole in those air cleaner snorkels! It sure did raise hell when you forgot to flip 'er back over before you went out bucking snow drifts, though!

ForceFed, I must just be a rookie, but I've never seen an air filter problem cause a plugged fuel injector.

[snapback]689077[/snapback]​

Sometimes the dirt never leaves the combustion chamber and will find its way into the injector O-ring seals. Its usually just a compression fit against the head in most cases. However unlikely, I thought I would just throw that out there

 

[froesen]

fix that manifold pressure sender first...the comp uses it to calibrate mixture, if you know it's bad, it's the first place to start!

good luck,
nik

 

[Party Chief]

Years ago, we used to flip the cover on the air cleaner to open up the element (remember that, you old guys???)

Jerry

[snapback]688248[/snapback]​

HA HA HA! Do I remember!?!?!? It made my old '78 K10 and '78 Jimmy sound like supercharged beasts! It made a hell of a lot more power than breathing through that tiny 1.5" hole in those air cleaner snorkels! It sure did raise hell when you forgot to flip 'er back over before you went out bucking snow drifts, though!

ForceFed, I must just be a rookie, but I've never seen an air filter problem cause a plugged fuel injector.

[snapback]689077[/snapback]​

Those old Q-jets made one hell of an induction noise with the lid flipped over. Those huge secondaries flow a lot of air. Some of that noise was probably the gas tank being sucked dry.

 

[skidoo'sbest]

fix that manifold pressure sender first...the comp uses it to calibrate mixture, if you know it's bad, it's the first place to start!

good luck,
nik

[snapback]689380[/snapback]​

Got a new sender in it and I'm going to clean the K&N and see what happens. Thanks

 

[CustomRev]

Years ago, we used to flip the cover on the air cleaner to open up the element (remember that, you old guys???)

Jerry

[snapback]688248[/snapback]​

HA HA HA! Do I remember!?!?!? It made my old '78 K10 and '78 Jimmy sound like supercharged beasts! It made a hell of a lot more power than breathing through that tiny 1.5" hole in those air cleaner snorkels! It sure did raise hell when you forgot to flip 'er back over before you went out bucking snow drifts, though!

ForceFed, I must just be a rookie, but I've never seen an air filter problem cause a plugged fuel injector.

[snapback]689077[/snapback]​

Those old Q-jets made one hell of an induction noise with the lid flipped over. Those huge secondaries flow a lot of air. Some of that noise was probably the gas tank being sucked dry.

[snapback]689453[/snapback]​

BAAAAAWAAAAAAAHHHHHHHHH!!!!

REmember That???

Jerry