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Discussion Starter · #1 ·
2009 SRT8 6.1L auto . I have ran scan after scan , sometimes with a CEL sometimes not , but when I do I keep getting a bank 1 lean . Have been through all the vacuum lines and find no leaks . I do get the infamous hesitation on lower rpm when giving the peddle a slow press .
I bought this car 3 yrs ago with 118k miles on it and it runs great but has done this since I've had it . The hesitation is only on lower speeds 20-40 not at highway speed . Also get Spark Knock sometimes when it happens , may be more but radio is probably up enough that I don't hear it Changed plugs and when I do things I only use OEM parts as much as possible. Pure stock except for High flo Cats I got from FastHemis . Have bought and switched around O2 sensors but no changes.

Any help is truly Appreciated . .
 

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I assume you are getting a P0171 CEL code.

This is caused by your engine having more than a 14.7:1 air-fuel mixture. This lean condition can be caused by a vacuum leak, which introduces more air into the air-fuel mixture, or by a weak fuel system, which does not input enough fuel into the air-fuel mixture. To keep your engine running properly, the PCM tries to compensate for the lean condition by injecting more fuel to the mixture in an effort to maintain the proper ratio.

Since you have eliminated vacuum leaks and O2 sensors as possible causes, I would check the fuel pressure. With an engine having 118,000 miles on it, you may have a weak fuel pump. Other causes to check are clogged or dirty fuel injectors or an exhaust leak.
 

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The Bacon Hauler (‘12 Cop Charger)
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Fuel supply would be my first suspect as well. Weak or dying fuel pump or clogged fuel filter screen in the main pump assembly.

How much fuel is in the tank now? If fuel level is low, add several gallons and try to recreate the DTC getting tripped. If it will not recur, the fuel filter on the main pump is likely clogged up.

Also, check the Fuel Trim PIDs. Compare one side against the other. If both sides are normal while in non-WOT operation, the problem should not be one of a vacuum leak or oxygen sensor, etc.
 

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2020 Dodge Challenger Hellraisin Scat Pack
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2009 SRT8 6.1L auto . I have ran scan after scan , sometimes with a CEL sometimes not , but when I do I keep getting a bank 1 lean . Have been through all the vacuum lines and find no leaks . I do get the infamous hesitation on lower rpm when giving the peddle a slow press .
I bought this car 3 yrs ago with 118k miles on it and it runs great but has done this since I've had it . The hesitation is only on lower speeds 20-40 not at highway speed . Also get Spark Knock sometimes when it happens , may be more but radio is probably up enough that I don't hear it Changed plugs and when I do things I only use OEM parts as much as possible. Pure stock except for High flo Cats I got from FastHemis . Have bought and switched around O2 sensors but no changes.

Any help is truly Appreciated . .
Vacuum leaks via vacuum lines is not the only source of an intake air leak. Intake manifold gaskets/o-rings can leak. The 5.7l engine has a tendency for its intake hold bolts to loosen. Could that be a problem with the 6.1l engine, too?

For finding intake air leaks used an aerosol can of carb cleaner. With the engine up to temp and idling I would spray carb cleaner at possible intake leak points. Hoses/hose connection, along where the intake joins the heads, at where the throttle body bolts to the intake. Around the oil cap on top of the valve cover. Along where the valve covers mate to the top of the heads. The oil dipstick tube.

If the engine reacted to the spray that was the leak.

As others have offered fuel supply issues can account for lean errors. In my (limited) experience fuel pumps either work or they don't but it is possible for one to work but work sub par and deliver insufficient pressure. The engine controller expects a certain amount of fuel pressure when it calculates the injector open times.

If there is a serviceable fuel filter and unless you have replaced this as just preventative maintenance -- and to some level throwing parts at the behavior -- replacing this is called for. And while you are at it consider the engine air filter and while not connected with the engine issue, the cabin air filter, too.
 

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2018 Scat Pack SHAKER in Plum Crazy- GONE :-(
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If the code is always for the same side of the engine, after swapping O2 sensors, I'd try swapping injectors. Taking a peek at the plugs might be a good idea as well, did any of them look different than the other cylinders?
 

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Discussion Starter · #6 ·
Just wanted to give a follow up . All cylinders firing good but one . Number three is getting a touch of oil only on half of the plugs. I was surprised that it went straight down the center . Waiting for valve stem seals to get here to replace . Doing all not just the one so I will let you know how it goes .
 

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Discussion Starter · #7 ·
Just wanted to give a follow up . All cylinders firing good but one . Number three is getting a touch of oil only on half of the plugs. I was surprised that it went straight down the center . Waiting for valve stem seals to get here to replace . Doing all not just the one so I will let you know how it goes .
Hey all , following up on what my issue was.

So on cylinder #3 I found a valve stem seal that was bad . Replaced whole side and put back together no more oil on plugs .

But another issue has came up . Number#5 gets random misfire code . Compression test on all cylinders are great and almost even . Fuel pressure is at 58 , book shows 53-63 , that is running and under throttle . New plugs , new coil pack but mainly appears when I put my foot in it . I did also try moving coils around but no change . No vacuum leaks .Nor exhaust I filled the pipe full on smoke but nothing . Also new injector

Any ideas ???
 
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