Fuel Injectors: Replace all or one?

[jegl]

2010 CX-9 FWD Touring with 185K

OBD-II Codes:
P0174 system too lean bank 2

P0204 injector circuit/open cylinder 4

P0304 cylinder 4 misfire detected

I’m thinking this is most likely a bad fuel injector for cylinder 4. With all the effort to get to the fuel rail and injectors, I’m wondering if it makes sense to replace all six injectors while I’m in there, even though I’m only getting the codes for cylinder 4, especially given the age and mileage.

 

[jal142]

I don't remember how much an injector costs these days but replacing them all is certainly the belt and suspenders approach. I'd measure the resistance of the injectors. They all should be roughly the same, within a few tenths of an ohm. Definitely replace any that aren't. The ones on the back of the engine are the painful ones to get to.

 

[jegl]

I don't remember how much an injector costs these days but replacing them all is certainly the belt and suspenders approach. I'd measure the resistance of the injectors. They all should be roughly the same, within a few tenths of an ohm. Definitely replace any that aren't. The ones on the back of the engine are the painful ones to get to.

Thanks!

The OE injectors I found seem to be around $60-$65 each. I got a quote from a shop that said labor would be the same if they did one or all six, but they’ll charge me $130 a piece for the injectors, so the total cost to replace all six would be over $1250!

I’ve removed the upper intake plenum before to replace the spark plugs, so I feel better about spending $400 buying parts on my own and putting in several hours of my own labor.

 

[roundle1979]

Should not be too hard. Watch a couple youtube videos:

 

[kornholio]

I would like to know can you replace the front injectors bank 2 I believe without removing the intake manifold? The injectors that I am referring to are the ones closest to the radiator.

 

[jal142]

I would like to know can you replace the front injectors bank 2 I believe without removing the intake manifold? The injectors that I am referring to are the ones closest to the radiator.

I don't think you can get the fuel rail off without pulling the manifold. If you watch the video above at about the 16 minute mark, you can see how the fuel rail and injectors are held in place. The rail is one piece so you unfortunately have to pull the entire rail and all the injectors off the engine to work on them.

 

[theblooms]

I'd make damned sure you actually have a bad injector first. They're pretty hardy. I'd look at a bad coil or wiring before a bad injector. Besides, faulty injectors can be cleaned in a sonic bath and returned to normal without having to buy new ones.