Hey guys,

My car has started to feel slow...flat would be a better way to describe it I suppose. The car pulls, but it doesn't pull like it used to in the higher RPM's...just starts to kind of flat line with no peak.
Cleaned the MAF and no codes seemed to be thrown.

My friends think my cats may be getting clogged, my car runs a tad rich, slowly causing the drop in power. There's no doubt there's a drop in power, aside from just feeling the power loss, it's noticeably slower when raced against an e46 330 and an e36 m3.

Any thoughts? I'm running out of ideas.

Kevlar I know you experienced cat failure...any experience similar to this?

Thanks!

How many miles?

Have you done any maintainence on it recently?

Changed the plugs?
Air filter?
Fuel filter?

If you have a beater - drive that for a bit - then come back to your car.

Maybe you've just gotten used to it....

Car is pushing 60k miles...all maintenance is up to date on the car with oil changes every 7k miles. So that covers the issue of plugs, filters, etc.

It's certainly not me having gotten used to the car. I'm certainly used to it, i put the last 50k miles on it, but that doesn't account for the car barely keeping ahead of a tuned E46 330i.

Could be the outside temps as well. As the heat of the summer comes, I have noticed some sluggish responsiveness from the engine. Heat is bad when it comes to performance engines.

C.

Not a chance, I've gone through summers before and know how the power loss feels...this is entirely different, like the car pulls and then just stops wanting to pull.

Not a chance, I've gone through summers before and know how the power loss feels...this is entirely different, like the car pulls and then just stops wanting to pull.

Do you have any datalogging equipment?

Do a couple of pulls. RPM vs. Timing etc...

Better yet - slap it on a dyno and SEE what's going on...

Any SES lights?

Chad

Nothing, which is why I'm leaning towards the cats being clogged and the car just adjusting itself to the restriction.

You know what mine has been feeling the same too and I am at 43k on the odometer. I am coming up on inspection 2 so that should help and I went to autox yesterday and beat on it for a bit and it was definitely pulling harder today when I drove it.

Is it a sudden feeling? Try changing gas companies...

Do you have an intake? I've heard cars with intakes are more prone to early cat failure. I have nothing to back this up now other than rumor.

As for my experience... I never felt any loss of power before the cats were clogged until the fatal day. Then it literally had no pull at all... almost as if somebody shut off the fuel pump.

Did you change the fuel filter?

my 05 m3 feels slow to me now cause i'm soo used to it:confused But whenever i have people in it they freak and think i'm wierd for not being scared for pushing it:( I think its time for mods.

i think mine is starting to feel slow too but i think its cause i have driven it about 26,000 miles in a 15 months. I think I have just gotten used to mine. ANd its going in for inspection 2 in two days so im sure that will help....

I have an intake and I have switched gas companies. Its weird whatever it is because the car feels fast again after a long highway drive or taking it up into the stratosphere of the speedometer.

what type of gas are you running? regular or the good stuff? that would definately make a difference.

I use 91 Octane Chevron gas.

That sounds low...

The standard in the UK is 95, Shell Optimax is more expensive but at 98 RON is worth every penny.

Each oil company has their own version of 'super' but most are 97 in the UK. Shell is the highest for sale in the UK.

I would strongly reccomend finding the highest RON you can get in the market and run it for at least three full tanks. You should notice a big difference!!

91 Octane Chevron is pretty much the highest quality gas available to me and the rest of the state of Arizona.

i've found that all the bmw's i've owned like 76 the best

for those of you not in the US, 76 is a brand not octane

kevlar what happened to your m3?

I use 93 and get it from chevron, mobil, or BP.

Maybe try changing the air filter... maybe it's clogged with dust/dirt.

there could be a lot of reasons why your car is feeling sluggish

do you have a air filter mod?

if its:

cold air intake - maybe hydrolock? some water got in?

short ram intake - sometimes when ur in traffic..ur engine can get heat soak because its sucking in hot air...which will cause a drop in ur HP

but like some other users said...maybe just get it dynoed and see whats up.

hope this helps

Problem is its a short ram on my car and the filter is clean and I will be moving at highway speeds and it will still feel slow. I want to get mine dynoed but my friends shop last time had a problem picking up spark but we think its his computer so hopefully this week or something I can throw it up on a dyno. I do however think it could be my cats and my problem is I am chipped for headers with no cats and so if something is wrong I will never know because its not going to even read that something is going on.