Hi all,

I have a '98 5.2 Durango with 88k miles. For the last 5-10k miles, I have been kinda hanging during acceleration. No check engine light has come on.... yet. It doesn't matter if the engine is hot or cold, but seems to do about 90% more often on a cold engine. Once I hit 3000RPM's, it kicks in a goes. Basically, it kinda feels like you're anticipating a sudden speed burst. Once you hit that 3000RPM mark, you're thrown back in the seat as the car takes off. Oh, and maybe every 1 out of 50 times this happens, I get a backfire.

So, after extensive research, here is what I have come up. It's either in dire need of new plugs (maybe gaps are off a tiny bit?) or it needs a new O2 sensor. Because I'm not mechanically enclined, I don't have the right tools to check the O2 sensor so I'm not too sure on either of these. Because of the backfiring, I keep thinking that it's the O2 sensor (lean/right mixture?).

Before I go out and start snooping around and buying parts, does anyone know which one of these it would be more likely to be or if it could be anything else? I've checked over the engine and I don't find any vaccum leaks or fluid leaks or anything else like that. I did forget to mention, however, that my city MPG has decreased from 12 to an average of 9.4MPG since the problem. Air cleaner is clean, oil has been changed, radiator flushed, and new hoses put on.

I'll stop rambling now, but I'm open to all suggestions!

 

Any time I have had this problem (3 times) in any of my cars, the O2 sensor was to blame. Its usually a cheap fix, and it should be done around 75k miles anyway.

 

Yep, I agree... most definately sounds like the 02 sensor.

But if it's been a long time since the plugs were changed, doing that too is good maintenance, although I don't think it's causing your above mentioned problem.

~Amanda

 

Yup, replace the O2 sensor, they burn out over time...

 

Next question.... I rented a O2 sensor puller and some rust-b-gone junk and tried to get the one before the Cat out. I cannot get the thing out at all. I even tried what someone suggested and ran the car before pulling it (generating heat to expand the area). That just resulted in a small burn, heh! Anyway, if I have to get it serviced in a shop, what can I expect to pay for both?

Oh yeah, and I have the parts already...

 

How many of the sensors are you changing-both, probably gonna run 300.00 or so assuming they can get them out. You didn't have any luck ,they may not either. May have to replace the headpipes and intermeadieate pipe.

 

I have a 2000 R/T with 49k miles on it. This R/T has been babied and garaged for nearly all of its 49k. Use preminum stuff on maintenance. Synthetic based oils, K&N air filters, heavy duty truck series champion spark plugs, etc... Power lags until it hits 3000 RPM's and then the SUV takes off. If it is indeed a O2 sensor, it should have turned on the check engine light? My check engine light works but is not turned on so the Durango is not telling me that there maybe something wrong. I have not attempted to have the computer display any codes if there are possible problems yet. Haven't had any backfire on mine tho.

 

If the Check engine light is not coming on, maybe its a part that not included in the codes.
Like fuel pump or clugged filter, spark plugs also might be giving problems, they ware of often.