This weekend I was traveling to see my girlfriend with the silencer in, I stopped at a rest area headed back out to the highway WOT and it shot out the back. The car seemed to actually get faster. No problems at all.

On sunday I let my roommate drive it to his parents house to pick some things up, and now I'm getting a popping noise I dont know if its backfiring? However its very frequent. When I'm decelerating or shifting gears especially 2-4 I'm getting a popping noise coming from the exhaust. My roommate is very competent when it comes to cars and I know he did nothing I would not do so I'm a little confused. I took the car out today and it just seems slow compared to friday, the temps are the same with almost no humidity.

Until this weekend I have never gotten any popping and have had the exhaust without any cats for almost a year.

I know i'm pushing my luck on the clutch I just hit 26K on the stock clutch and I've been making 300+WHP for over 18K miles so could this be a reason?

Basically, what are some things I can check to see if I can get this fixed?

I'm going to pull my plugs right now and do a compression test, i'm holding steady at 1.5 bar to the normal taper to 1.3

Any ideas or help?

thanks so much!

 

Does it happen w/o the silencer? Maybe it's causing a rich condition?

 

Well, the silencer is some where on I-95 so I cant recover it. However I drove the car for 15K miles without the silencer and I had just put it in on my last oil change about 1K miles ago and it was running great. When I heard it rattle and then fly out my car felt much faster.

My car is tuned rich but it has been for the previous 15K miles so I know how it "should" feel.

thanks for the help

 

Here are the pics from the sparkplugs...

http://www.d-rail.com/test1/spark.jpg

http://www.d-rail.com/test1/spark1.jpg

http://www.d-rail.com/test1/spark2.jpg

those are Denso IW-22 with about 8K miles!

Also I just remembered my roommate drove my car to the 250 mile mark, so it was on fumes. I always fill up at 200 miles, could this have caused the sediments from my fuel tank to have clogged the filter?

 

of course your car is going to feel faster without the silencer in, because very simply, it is! the silencer chokes the exhaust, making, in turn, less power.

 

Hey on the pics of your plugs it looks like the iridium tip was gone on the pic also you have deposits that can be caused by leaded gas or the poor gas quality we have had lately after the hurricanes also if the plugs are blackened the O2 will look the same take it out an blow it out with an air compressor

 

Just installed some NGK bpr7es as recommend here on the forum and she fired right up and all problems are now gone.

thanks for the tips I'm deff gonna check my o2 sensor next oil change

 

Nice!

For future reference:

 

Nice post

For the record, how often should the iridium plugs be changed?

 

those plugs were cashed and looked very hot with small amounts of melting, the white color on them. i would go to 8's on your car to get the heat out. the small amount of carbon around them means the A/f is good

 

I've got those plugs, work great. Hm...it might actually be time again to change mine out. How many miles is everyone changing theirs?