Well my 03 eco finally threw a code last night telling me my system is too lean. Ever since the cold weather showed up I've noticed a significant loss of power after around 3k rpm.

Also, I. Know I have a vaccum issue because when I disenngage the clutch at any rpm, the engine drops to around 6 or 700 rpm, struggles, and comes back to around 1k (which is actually higher than my 800ish normal idle)

Ever since installing my aem intake last winter, I've had issues with the damn vaccum line gromet and iat gromet. Could this be causing my issue? To me, any air that seeps passed the intake gromet would not affect my 02 sensors reading. Can anyone explain this? I've replaced the gromet for the vaccuum line with a gromet from a kit but the issue is still there. It is tighter, but still not solid. Any ideas?

Thanks

Anyone?

Get you a can of Carb Cleaner. Spray down that grommet and spray down your intake manifold, and injectors and such. Where ever you spray if the engine starts to bog hard when u spray in that area then that will tell you where your air leak is. I dont think that grommet will cause a lean code. Im thinking more along the lines of a intake manifold to block air leak or as a similar situation I had with my girls old vert there was air leaking right around the injectors. So do the spray test, and fix accordingly. Goodluck!

I have to add to what Sneezy said. The base of the spray will make a difference with the results of actually spraying to find a leak. You need to make sure you use an alcohol base spray or that the carba dn choke cleaner has a flamable base to it, otherwise, you won't notice any difference in the way the car is running.

Second, it may just be the O2 sensor itself. Most commonly, when I was working on those for a living, that is what the problem was. I'm not saying it is your problem, but the most common problem I personally have seen was the O2, with the exception of my own Cav which has a P0171 that won't ever leave even after throwing everything possible at it including the kitchen sink...

And third, any vacuum leak you have before the throttle body would most likely not have any effect on the MAP readings or the air/fuel mixture. A vacuum leak before the throttle body would still be corrected by the IAC solenoid or the throttle blade, the computer controlling one and your foot controlling the other. Not having a tight grommet around the IAT sensor would be like not having any kind of intake snorkle on the car at all, maybe not that severe, but similar. The IAT will still measure the air temperature around it, or any ait that is still whipping by it, but an air leak around it shouldn't cause an idle issue or a lean code.



Some people have brain storms, others light drizzles. And then there are those that have droughts.

Thanks for the help, I'm heading out to get what i need now.

Is it not true then that for the CEL to to run p0171 that the computer first verifies the condition of the 02 sensor to validate the out of normal reading? I had read that somewhere.

This is going to be hard to explain. You already know that there are a whole bunch of sensors on the vehicle that feed information to the PCM. The PCM is programmed to recognize specific readings from each and every sensor based on driver input (IE throttle position, gear selection, clutch pedal position, etc), operating temperature for specific component like the engine or transmission, vehicle speed (compares each wheel speed sensor and the VSS with each other), ambient air temperature or intake air temperature, oxygen concentration in the exhaust, etc. It takes all these inputs and produces an output to other various components like the fuel delivery system, spark control module (ignition module), etc. If it has a sensor that is picking up a bad reading or if a sensor produces a reading out of the expected parameters, be it during initial start-up or after running for a period of time, the PCM will instruct the check engine light to come on. It will store the code or codes that are producing a bad reading. Now, what is causing that bad reading can be a number of things. Sometimes it is simple, other times it can be a rather huge pain in the a$$ (as is the case with the P0171 I have on my 02 Cav with the LD9). You need to figure out what is causing the sensor to produce a bad reading, be it something on the intake side of the head, an exhaust leak in front of the sensor, the sensor itself, or something else, that is causing the light to illuminate.

My recommendation is to find someone with a scanner that you can watch live data on and observe the O2 data. 90% of the time, this will lead you right to the problem. But a code reader isn't going to be enough, simply because all it does is tell you what the specific code is and a brief description of the code. If you can see the O2 data, and you spray the intake side as Sneezy recommended, then you will see an abnormal fluctuation in the readings. If this occurs, then you have an intake or vacuum leak somewhere. If you don't find a problem on the intake side, get under the car while it is running and feel around for an exhaust leak before the O2 sensor while the car is running. Be careful not to touch the exhaust though as you know it will be very hot. If you discover nothing doing this, throw an O2 sensor at it and see if that doesn't fix your problem.



Some people have brain storms, others light drizzles. And then there are those that have droughts.

Thanks alot for taking the time to go over that. I do appreciate it.

Ill have to see how in the world I'm gonna get my hands on a scanner capable to do more than codes. I took the carb cleaner to every vacuum component i could find, and didn't notice any fluctuation. I also had my fuel pressure tester on and ran it through 3k rpm where I notice the power plateau trying to lead me somewhere. Ill be checking for that exhaust leak tonight. I'm hoping it's just the sensor, but we'll see.

I will let you know! Thanks again.

Thanks for clearing that up JCZ Z24. Also I just wanna add, if it does just turn out to be a O2 sensor, as he said, which is very possible, STAY AWAY FROM BOSCH SENSORS!!!! I installed one into my girls car, and it never fixed the issue, and installed a diffrent one, and boom, problem fixed. For some reason they dont like our cars, and never act right, normally giving off a bad heater element code (Cant recall the exact code ATM) but it wont fix anything but instead will send u into another tailspin trying to figure out WTF is the matter lol. Goodluck, and keep us posted!!

Looks like I'm headed to the parts store for an O2. I can't find any leaks for the life of me.

Might be till Tuesday night before I get a window of decent weather. Most businesses locally are closed.



I will keep you posted!

Should i be looking at the pre cat o2 correct? Im new into this engine performance area. Doesn't the post cat sensor measure just unburned fuel/oil?

Also. What do you think about denso?
Where can i go for a budget o2 that will work? The budget is tight at the moment. I have Auto zone gift cards but they carry only Bosch and denso according to their website.

I picked up a Delphi from Federated on my way home from work yesterday, and just finished it up.


No luck .

Still a HUGE powerloss right at 3k RPM, I'm starting to thing its a fuel pressure issue. I dont think i have any restrictions, as that would cause any RPM or even idle to run funny. The pump i have in there worked fine for the 8 months it has been in, but it was a cheap rebuild kit from EBay.

To see if this was it, i hooked up my fuel pressure guage and reved the engine to ~3k RPM. Upon hitting the pedal the pressure would drop a few PSI, but recover very quickly (which i assume is normal) and the pressure stayed consistant when i held the throttle at 3500 RPM. Does the pump work harder under load?

Im running out of ideas here, and i dont have the money to throw parts at it.

Thankss

When u say no luck, did u clear the code, or waiting for it to turn off. If you havent cleared it, do it. Also, iit is VERY possible that ur pump rebuld kit is just taking a dump. Also, when was the last time u did a fuel filter? Also, while the car is running, pull the vacuum line off the FPR. Does anything come out, if yes, replace the FPR if not turn the car off and smell the line. Does it smell like fuel? Yes then replace. Check those, and get back to me. I think ur right about a fuel problem. Im willing to bet that ur pump maybe taking a do-do. But before we do that what was the PSI holding at when u did the fuel pressure test. Ill do some digging and see what the specs are for ur car, and talk to a few people tmo. Also, i would get a new fuel filter bc u will need it anyways. The jump u had really should not have been there when the pedal was pressed. It should increase right away. Let me know, and we can go from there.

Hey Mike,

Your a late night dose of hope for me lol

Yes, i did clear the code. It took roughly 20 mins for the car to throw the code again. It did so at idle, strangly enough.

I replaced the fuel filter when i did the pump.



As far as the other troubleshooting steps, I will repost in the morning with everything you suggested including the systems PSI.


Thanks again for all the help. Driving the daily driver in this condition is a real downer.

Just did the fpr tests you suggested. It did not throw fuel at me, but the line does faintly smell of it.

Can you explain what's happening/could be going wrong with the fpr and why? Just want to know what I'm looking at. I haven't had time to check the psi again because of the holiday. I will for sure later on tonight though. I may even be able to take a vid.

Slowly but surely

I took a video of my fuel gauge while i put the pump to work.

Hopefully this can help us narrow it down. I'm not at all sure what normal PSI readings it is supposed to put out. So you tell me. Also, like i said above, the vacuum line does smell of fuel.

Really hoping i don't have to put a fuel pump in this thing.. I'm tired of dropping the damn tank lol.

Ok, great vid, and that shows whats going on 100%. When the FPR has a smell of fuel in the line, that means the diaphram inside of it is going bad, meaning its not regulating the fuel like it should, so I would replace that just bc. Its not 100% bad right now, but it will be, and it dont take long for that to happen.

Now after some quick googling, I found out that supposedly the stock ecotecs are suppose to have between 44-50psi at idle, and 55-60 during wide open throttle, and ur needle didnt move, infact it went down actually, and dropped, after revving, to 32-33psi. And when u did rev it, it dropped for a split second, and then stayed where it dropped to, and never came up. Im thinking now the problem lies with ur fuel pump. Unfortunatly thats the only thing I can see is the problem. Its just not getting enough fuel to the injectors. Hense the lean code. Ill get some more ideas from a few friends to make sure im 100% right, until then, sit tight, and ill have some answers for you by the end of the day.

Ill grab the fpr tomorrow, any installation tricks/tips?

I have only myself to blame for buying ebay car parts. The pump was to be temporary anyway as cash was tight. Ironic though that's the same story now lol.

Well ill keep checking back on the final say, what I'm hoping to hear is " its all the regulators fault" lol.


Thanks again mike, you've been a big help.

Here, they said install the new FPR and then test the pressure again. If it dont change then its the pump. If it does, and goes up, ur good. Then that should fix the lean code. Normally a lean code means a vacuum leak somewhere, but since u did the engine running spray test, and nothing happened, then ur good on that aspect. Try that and let us know. We already think the pump is going bad, but since there is a smell of fuel in the vacuum line the FPR should be changed reguardless. Worse case senario, U will fix one problem that is small now but can cause issues later on. And no problem, Im here to help. I know I have posted many topics of help when i needed it, and now im just trying to return the favor.

Ill post back to update any searchers of the future.

I'm in school for auto now, but its seperated by modules and am only a few months in. Some systems I know, others I don't, yet. Its a lot more expensive than I thought it'd be, but I have no other way to learn it lol

Crossing my fingers on the FPR, but I know I'm dreamin

Actually, it very well could be ur FPR. Especially since its acting the way it is and not letting full pressure go to ur injectors. It maybe the pump, but the FPR (altho cheaper then the pump, but still not very cheap) is better then just guessing. ATM, ur having that fuel smell in the line, which tells me the FPR is going bad. That would be the 1st starting point. Then if the pressure doesnt change, its pump time.

Hey man, I dug a bit deeper. But according to AZ's repair manual, your fuel PSI should be between 50-60 psi. click here and go to 2003 and it will show you what ur PSI should be at. Unfortunately it seems as if the pump is going poopski. Sorry buddy.

i would still wait on the pump for the fpr to go in. you know its bad, so don't replace anything else till you replace what you know needs it.

also, the hvac vents are vacuum actuated...were those tested???

Put the regulator on today..

Still, no change. May have even gotten worse,


Fuel pump it is.

Yeah i figured it the pump wasnt putting enough pressure. Get that changed out, and keep us posted. Sorry to hear about that tho.