Quote:Originally Posted by GertFrobeThe modified exhaust is fine, the engine doesn’t care about it in terms of idling. If anything it might be breathing a little easier with that non-stock exhaust if not as restrictive as stock setup.

The aftermarket air intake is also theoretically an acceptable mod for that engine, and it does not require, nor would it benefit from, different fuel injectors being installed. The stock injectors can spray more gas than the engine could ever burn, even when it’s ingesting the absolute maximum amount of air that it possibly can at WOT.

Different injectors might be necessary if you had forced induction on the engine (turbo, super charger, nitrous) to feed it more air than normal atmospheric pressure can normally force into the combustion chambers, but the stock ones are fine as long as the engine remains naturally aspirated.

That does not mean the aftermarket air intake is not the culprit here though. In fact, I suspect that it is causing the erratic idle, even if inadvertently. It’s the first thing I would check if it were mine anyway. You should start your troubleshooting with it and it’s components either way, attempting to rule it out as the cause so you can move on and find what is causing the idle issues.

First, take the whole thing off the engine and completely disassemble it for inspection. It should only have a couple major pieces (intake tube, air box, and filter) and a few smaller ones (filter, clamps, elbow sleeves, breather hose), so a complete disassembly isn’t that difficult to do, but it is absolutely required to be able to rule it out as your cause (or find the proof that it is guilty of something).

Once apart, carefully inspect every joint, junction, and connection point on the device where it supposed have an air tight seal with some other part or piece. You are looking for signs that it is no longer sealing at one of these spots and thereby allowing the engine to suck in unfiltered air. Small dust trails of very fine dust will be a dead giveaway that an air leak has formed somewhere, and they are more common than anyone wants to admit on the aftermarket air intake systems like this.

Pay very close attention to the air filter element itself, especially where the element and wire structure are connected together. I have seen those types of filters develop leaks there from inadequate or too much epoxy being used during manufacturing assembly. Again, look for faint dusting on the surfaces adjacent to the join-surfaces to identify potential leak spots.

Also inspect the areas on the intake hose where the hose clamps normally reside. After a lot of miles and time, that rubber hose will begin to deteriorate and break down to the point of becoming brittle and prone to leaking under the stress of the (usually overtightened) hose clamps.

If you go over the intake system and cannot find evidence of an air leak, time to focus on the intake plenum that the air tube was attached to. It has several hoses and pipes that connect to the back of it, under the windshield cowl, and they are all supposed to be air tight too. But they will develop leaks as their hoses age and start to harden up. The EGR pipe connection point is especially bad about leaking if it has ever been disconnected and reconnected (like for a spark plug replacement).

The gasket between that intake plenum itself and the engine block can develop a leak as well, so that would be my next point of inspection if none of the rest panned out.

By now you might notice that are getting elbow deep into the engine, and as such you should consider changing things out that will be easily accessed during all this, which is likely required anyway if normal maintenance schedule is being followed.

New spark plugs, new PCV valve, serpentine belt, idler pulley, belt tensioner, a cleaned out intake plenum, etc...

Depending on many miles the engine has and how well the previous owner took care of it (or didn’t, hard to know without finding out for yourself), those things and more are due for replacing/cleaning and should not be ignored lest erratic idling becomes the least of your problems.

Don’t forget the timing belt, its tensioner, and the water pump either. Those are supposed to be changed every 100K miles, as is the engine coolant. Granted none of those are likely to be causing your idle problems, but if any of those are left too long in service, you could lose the engine for good with little or no warning.

But I digest...

How many miles are on the engine? If > 100K, you have a lot of maintenance services to consider performing while chasing this idle issue. My advice would be to buy a 2005-2010 Dodge LX Chilton’s Manual from Amazon or a local auto parts store and start making a list of what needs to be done and what can wait.

That manual will have some generic steps you can try to calm an erratic idle, but don’t put too much hope in the troubleshooting section of those manuals. Their one-size fits all approach to covering as many applications as possible doesn’t lend itself to being very useful when out to the test on the average joe’s broken vehicle.

One last tip: go to [MyCarFax]DOT[com] and create a (free) account there, providing this Charger’s VIN as part of the account sign up. That will allow you to see any of the vehicle’s service history that has been reported to the CarFax company.

You may find no entries at all, in which case you’re no worst off than you were before. But you could get lucky and find the previous owner took the car to places that reported their work and you’ll have a good idea of how well the car was maintained as well as if any severe problems or damage was in its past (and may need to be dealt with again).

Pretty good for free!

Gert