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Discussion Starter · #1 ·
forgive me if this issue was discussed in the "raw gas smell" sticky but I wasn't quite sure..

Ok here's the deal, about 6 months ago I fired up my bugeye and the car puffed black smoke, idled extremely rough, and barely had power both at low rpm's and low amounts of throttle regardless of what gear I was in. I limped a few miles home and didn't drive the car until the next day. It ran fine, as if it never happened which left me quite puzzled.

I didn't have any other issues with it until this past february. On a cold start, it showed the same symptoms once again. Ever since then it's progressively happened more and more over the past few months. Even more puzzling, I was on a road trip recently (bout 500 miles) and was cruising down the highway when all of a sudden I noticed that the car started to studder and lose power. My boost levels went up about 5lbs also. I pulled into a gas station and noticed the same symptoms that I had dealt with before...stuck in the middle of nowhere..I had no choice (work two jobs) but to limp home on the highway...getting 11-12 mpg...no joke...I pulled the codes on my access port and the car is throwing both "bank 1 too rich" AND "bank 1 too lean"

This is not only costing me ridiculous amounts of gas money (91 oct is $3.90+ around here) but I can only imagine what it's doing to my vehicle..PLEASE HELP :(
 

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You have modified the car but did not list how.

You have CELs but did not list which. I am guessing your codes are PO172 and PO171.

I have never seen the two codes together. They are both dealt with in the same manner WRT troubleshooting -- check for leaks in intake, boost control, and fuel pressure regulator feedback, correct MAF problems (clean it usually), correct filter problems.
 

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Discussion Starter · #3 ·
sorry list of mods should be in my profile and yes they're PO172 and PO171 which is what confused me most. I'll check for intake leaks first and start from there I guess.
anything else? thanks for being patient
 

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I can't think of something because both codes are simultaneous and that's confusing me. I'd start by looking closely at anything/everything related to the MAF, as it can generate both codes. Other than that though sorry, I'm confused.
 

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How long have you had that list of mods on there? What kind of tune are you running? Other than the change of the clutch, is there anything else since then you've done to the car?

What about when this first started? Same questions. You say it started 6 months ago but something must have happened to start it.
 

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Discussion Starter · #6 ·
How long have you had that list of mods on there? What kind of tune are you running? Other than the change of the clutch, is there anything else since then you've done to the car?

What about when this first started? Same questions. You say it started 6 months ago but something must have happened to start it.
I purchased the car in march of 2010 with all of the mods installed on it. I was told the car hadn't had anything installed or added for 10000 miles. I'm running the basic shelf map 91 oct tune from cobb for a VF39 w/ 565cc pinks, nothing fancy. Nothing out of the ordinary happened. I was at sonic getting some food, I fired it up to leave and it barely ran and showed the symptoms I mentioned. However, even more strange, it doesn't do it all the time...there are times (more often than not) where it runs perfectly fine and boosts just as it should without the codes...
 

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I wouldn't be running a stock map with those mods. The first thing I'd do is get your car properly tuned.

How many miles are on the car total?
 

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How old are the plugs? Is the timing belt original (if so replace it NOW)? How often do you change the oil and filter and with what?\\

Given the odd code combo I have a lot of questions to ask...
 

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Discussion Starter · #10 ·
timing belt was changed at 72K however the plugs are unknown to my knowledge. I would have changed them already if I could actually reach them..
I run mobil 1 full synth 5w30 with the standard wix filter. oil gets changed easily within 3k miles
 

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I'm trying to think of an explanation for loss of fueling control. The FPR I suppose? I don't know...

Bumping thread to top for help...
 

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O2 sensor or MAF problem is my guess. Those are the two main components that help the ECU determine fueling. Could be fuel delivery related as well. I would recommend checking ALL wiring to make sure the connections are good to at least the O2 sensor and MAF, clean the MAF sensor, probably a good idea to change out your fuel filter as well. Pull out your spark plugs and check them to make sure they haven't fouled out, because with the symptoms you're describing they will start to go down hill very quickly.
 

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I don't know if I've ever heard of a MAF causing such a rich mixture that the car throws black smoke, but anything's possible.

Even if they're hard to get to, your plugs are the first place I'd look. Even if they're not the issue, their condition could tell you a lot.
 

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Discussion Starter · #14 ·
thanks everyone i'm gonna hopefully turn some wrenches this weekend (my free time is zero to none)
i'm also driving the car as little as possible for fear of serious damage. for all i know i could go out there and it'll fire right up and run fine. who knows. once again, thanks and i'll try to keep everyone updated.
 
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