Weird power drop..

[Guy]

Hi guys,

I have a weird problem where my '05 idles fine and drives fine up to about 2500-3000rpm and then starts to sound more "high pitched" than usual, almost like I lost a few cylinders, and has a significant drop in power when gong up to higher revs 4-5K.

No smoke, backfiring, misfiring whatsoever. Aside from the noise and the loss in power, it all seems normal; very strange. I have a 100% stock engine and exhaust setup.

Any help appreciated. I will try to check for codes with my Craftsman scanner, hopefully it'll show something.

If I had a couple of fouled plugs, I would have black smoke coming out of the exhaust, right? Could it be retarding timing for some reason?

Thanks in advance for any help!

 

[JonB]

Make sure the obvious that your airbox / filters are clean.
Miles on car?
Stock Motor noted....

High miles, could be wires or plugs or even injector issue...Fuel Filter?

Check Engine Lites? Could also cam-crank sensor....

 

[Guy]

Hi Jon, thanks for a reply! I was starting to get worried

- 2005
- 10,500 miles
- Completely stock engine, exhaust etc..
- Oil level perfect (oil changed 800miles ago)
- No check engine light
- Normal low-rev behavior..


Any quick checks I can make to check the cam-crank sensor?
As luck would have it, I have a fuel filter on order (it takes my local dealership weeks to stock Viper parts..). Should be here this week. Will definitely change it!

 

[JonB]

If it is one of the sensors, a computer-read at the dealer can be a help....
I do suspect ther have been some CELs? {chek-lite}
That low miles your plugs and wires should not be an issue...

 

[mjorgensen Woodhouse]

Sounds like a plugged cat to me, but that should be throwing a CEL. Maybe there is something going on inside the stock muffler, maybe the cat came apart and is caught in the exhaust causing the change in pitch at higher RPM along with blocking airflow at the higher range?

 

[Guy]

Hey guys,

Thanks for the replies. Time to put the car on a lift, I reckon. Definitely no CELs...

Any danger in running the car cat-less on a stock exhaust semi-temporarily? I am of course assuming that I can build cat-bypass pipes and that they'll bolt in instead of the cats..