Car running lean

kenshi

Registered User
Ahoy. Whenever I drive my car for a few miles the check engine light comes on. When I check the codes, it gives 41 and 91 (both sides running lean). It also says this after a KOER test. The car performs well though (considering I don't have the blower belt on). I recently fixed a bad vacuum leak and then reset my computer, but it didn't go away. I also recently changed my fuel filter. I really don't think it's my fuel pump because it usually happens when cruising, not accelerating, when there's no heavy demand for fuel. I just bought new HEGO sensors. Also, it throws codes 33 and 25 on a KOER test. The 33 code indicates the EGR valve isn't opening, but it never has this code in continuous memory. The 25 code (no KS detected) worries me. I have yet to hear the engine knock though. What do you guys think? I hate to keep throwing money at parts and services without being able to diagnose the problem.

One other thing, I have two loose vacuum lines. One goes to the windshield water tank. I would guess the other one connects to it but I want to make sure. Neither line has vacuum with the engine running so I don't think it has anything to do with the above problem. Anyway, below is a picture. Is there supposed to be something special that connects the two hoses or just a standard vacuum hose connector? It seems like there was a one-way valve or something on it before.

vacuum_hoses.jpeg
 
Your no Knock Sensor code could be related to not running the KOER test properly. You have to "goose" the throttle at the appropriate time while running the test to get the sensor to "pick-up" and send its signal to the EEC. If you are using one of those cheap code readers you never know when the throttle needs to be goosed...hense you get the code.

As far as your lean problem....fix all your vacumn hoses first. Any chance your exhaust manifolds are glowing red? Might be your harmonic balancer is broken. See if your crank pulley wobbles any with the engine running. MAF Sensor wires clean? Might also want to clean the MAF connector and make sure you have dielectric grease in the connector. Lean condition can be caused by a myrid of things which all have to be checked. Took me almost 2 years to track down an intermittent lean condition. I felt like a fool when I spent all kinds of money and it turned out to be a dirty MAF connector.
 
I cannot help you with your first question, but I wouldn't connect the hose from the windshield washer reservoir to a vacuum line because the washer fluid will be sucked into the engine. The hose from the reservoir branches out to the two windshield washer jets under the cowl plastic covers. The hose is for washer fluid only, not vacuum.
 
Duffy Floyd said:
Your no Knock Sensor code could be related to not running the KOER test properly. You have to "goose" the throttle at the appropriate time while running the test to get the sensor to "pick-up" and send its signal to the EEC. If you are using one of those cheap code readers you never know when the throttle needs to be goosed...hense you get the code.

I goosed it whenever the single light flashed. Before when I didn't, it gave another code about insufficient TPS voltage and RPM change during dynamic test, so I figure I did it correctly.

As far as your lean problem....fix all your vacumn hoses first. Any chance your exhaust manifolds are glowing red? Might be your harmonic balancer is broken. See if your crank pulley wobbles any with the engine running. MAF Sensor wires clean? Might also want to clean the MAF connector and make sure you have dielectric grease in the connector. Lean condition can be caused by a myrid of things which all have to be checked. Took me almost 2 years to track down an intermittent lean condition. I felt like a fool when I spent all kinds of money and it turned out to be a dirty MAF connector.

The exhaust manifolds have never been red when I popped the hood, but I can't exactly check them going down the road. The balancer doesn't wobble when the engine is running. I've had two of those break on my LX so I'm paranoid about that. I recently cleaned the MAF and the terminal looked clean. I know a lot of things can cause it, and that's why I'm asking for further troubleshooting steps. I've checked everything I can think of.
 
Picture is kinda sketchy, might be line that connects to the PCV line off the pass. side valve cover and runs down by the fender.
 
J.D. said:
I cannot help you with your first question, but I wouldn't connect the hose from the windshield washer reservoir to a vacuum line because the washer fluid will be sucked into the engine. The hose from the reservoir branches out to the two windshield washer jets under the cowl plastic covers. The hose is for washer fluid only, not vacuum.

Well I called it a vacuum hose. It's not pulling a vacuum with the engine running though. I put my finger over both hoses to check this. It probably is the water hose. I just wanted to verify it and ask how they connect since I only have two hoses there.

sonicman1634 said:
Picture is kinda sketchy, might be line that connects to the PCV line off the pass. side valve cover and runs down by the fender.

Wrong side. This is on the driver's side under the master cylinder for the brake. The large bending tube at the top of the picture is my lower intercooler tube.
 
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