multiple misfires/ bank 1 and 2 O2 sensors
 

Hello,

I have a 2004 Sante Fe 2.7L that I am having a couple of issues with. I am having multiple engine misfire codes (P302, 304, 306) that are showing along with P1167/1177 (bank 1 and 2 forward O2 sensors (running lean). Vehicle has 133,000 miles on it and I live in Hawaii. I have only owned it a couple of years so I am not ware of anything before I bought it. So other than the CEL being on, the issue is the car will not accelerate. This only happens on cold starts. Not that it is cold in Hawaii but if the car has sat overnight or a couple days without running that is when I have the issue. I can start it and tell the engine is misfiring and it will not accelerate. I can pull over and turn the car off and then immediately back on and the issue will not be there. The CEL never goes away but the car will accelerate and run like everything is ok. Spark plugs have been replaced recently as well as the fuel filter. I also have cleaned the MAF sensor and checked for vacuum leaks. No vacuums leaks that I am aware of. I went ahead and had replaced both O2 sensors as well. I don't want to really continue the guessing game and pouring money into a vehicle with this much age on island and that I can get to run fine by turning it off and back on but nevertheless it is very annoying and something I know needs taken care of. I was looking into possibly replacing the coil packs and wire plugs next but from everything I tend to read this usually is not fixing the problem on these vehicles. Any input would be greatly appreciated.

Has there been any recent work done on the vehicle?
Just wondering since cylinder 2, 4, 6 are on the front side of the engine
Misfire could be caused by vacuum leak
Try spraying water near the cylinders to see if the misfires stop (cold start)
Try a power balance test with a scanner watching the misfires
Sometimes a bad coil will pull down the other cylinders (rare)

The only recent work is when I replaced the plugs a month ago and recently replaced the fuel filter 2 weeks ago. I don’t have a scanner to take a look at the misfires but I can try spraying cold water like you mentioned. Can you be a little more specific as far as spraying and what I’m looking for when I’m doing that test?

When did the misfires start?
A month ago? Or recently?

When replacing the spark plugs, did you use NGK platinum or iridium OE?
(I had changed my spark plugs with cheap one. A month later, I had to get the good ones and replace them again)

Spraying water, when the engine is cold, near the in-take manifold and air filter tube and near the plug wires
(don't flood area)
To see if there is a vacuum leak
And to see if there is any spark jumping to ground

The plugs are cheaper ones (Autolite double platinum APP3924). Honestly, I've had the car as an island beater for 2 years and the CEL has always been on but I never really saw any performance issues or anything else that stuck out. I would say the misfires and being able to tell a difference in the performance started a couple of months ago. I actually took a look at the plugs again and they look like crap as well as a gaps are different on each one and a couple at the maximum limit. I went ahead and was going to inspect the plug wires the other night and they also looked like crap and 2 of the leads actually pulled out. With that being said I am going to replace the plugs again along with the wires this time. I also have done some reading where people have had issues with the crankshaft position sensor as well. Since I am already tinkering around and taking things a part I went ahead and took a look at it. One, it was loosely installed. The sensor could be moved a bit and the 8MM screw holding it in place could be taken out with my finger. I removed the sensor and it is completely gunked up and all the protective shielding for the wires has been worn off with exposed wire strands everywhere. I found a replacement for $12 and it is en route with my plugs and wires. I will install the new parts and put everything back together this weekend and hopefully have a better running car.

Thanks for the update. Really appreciated.
Hope all those things help to rid you of those misfires.
Good luck

So an update on everything going on. I replaced the parts that I had listed earlier in the thread. The car was running much smoother it seemed like. Felt like I had more power and shifting much smoother. I drove the car probably 30 miles and let it run for about 30 minutes with no issues. Once I turned the car off and back on the CEL came back on. Before I got a chance to have it scanned I was going to go ahead and clean the throttle body and install a new plenum gasket since I've had the manifold opened numerous times. With that being said, I went to pull off the air intake hose and it basically pulled completely apart. I noticed it had some major deterioration on it and its no wonder it pulled apart. I have the part on order and it should be here by this weekend but for now its back to sitting in the garage.

any updates on this? i am having similar issues with my 2003 SF.