Problem - CEL on and car seems very under-powered

[sashman15]

Disclaimer: I'm a total newb when it comes to working on a car, but if you could give me some sort of idea on what I can do to fix this, it'd be much appreciated.

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Background: So I autocross'd my automatic 2003 Mazda 6i, bone-stock, twice now. Also did some more-than-spirited driving recently on Deal's Gap, which actually felt like it beat on my mazda WAY MORE than an entire day of autocross.

Ever since Deal's Gap (about 2-3 weeks ago now) I've felt like my Mazda 6 feels a lot weaker. When it idles it kind of sounds normal, but when I tap the gas lightly and start cruising at low speeds maybe around a parking lot or something, it feels like its struggling to move and at high speeds I just dont feel comfortable.

The CEL came on a few weeks ago, I believe prior to the Deal's Gap beating of my car, and it ended up just being a coolant issue, so I added some coolant and the CEL went away. Yesterday I was testing my car and giving hard throttle at random moments in a 5 minute period whilst cruising around the neighborhood - safely, just testing the car's response, it felt like it was able to do what I wanted it to, just not very confidently.

Today I sit in my car, turn it on, drive out of the neighborhood on my way to work ever-so-calmly and slowly, and the CEL pops on again.

Main Question: Should I flush my cooling system? Or do you guys think this has to do with something else? Car has 145,000 miles on it and has been driven hard a lot of the time.

[highwayracer]

Have you pulled the code? If you don't have a code reader, Auto Zone and I believe Advance Auto will pull the code for free. Once you find out what is throwing the code, come back here and post the results, and we can move to correct the problem. Until then, you're just shooting in the dark.

And remember, this advice is free and worth what it costs!

[sashman15]

thanks for the reply highwayracer

Well the main thing is, the car felt pudgy and weak BEFORE the CEL came on. So the CEL isn't my primary concern, but it is something I'll check out asap. I was hoping someone could give me some insight onto the 'symptoms' my car is experiencing.

What could cause a car to feel weak or resistant to throttle?

[leetaylor92]

CEL may cause a car to run at 50-75% performance if the issue is not fixed. I had a VW that wouldn't run at 100% no matter code or not, it knew something was wrong no matter how many times I cleared the code. Once the issue was resolved the car performed at 100%. May be the same for Mazdas. Just a thought.

[stealthgtfour]

sounds like a fuel mixture problem. if it has a lean code it may possibly have
a large intake leak such as the intake boot having a crack or it may be dislodged.
visually inspect all hoses, clamps, connections, etc. youd be suprised what you might find.
the code may be related to the poor performance so definitely check it.

[sashman15]

CEL is what it said before - coolant problem. P0128, coolant thermostat or something.

Could that be causing the problems I mentioned? The car just feels not as thrilled to go fast compared to about a month ago when it felt peppy and jumpy (a good kind of jumpy).

im not good with the mechanic lingo btw as you can tell lol

[philip1]

Is the car under waranty? If so take it to the dealer and say fix it.

[cr89x]

Ditto on Phil's comment. 128 is for Primary O2 Sensor B1S1 not coolant. Have you still been losing coolant? I would look at the spark plugs if your still having a low throttle input issue and intial throttle input.

[sashman15]

I don't know if I've been losing coolant. And no the car's no longer under warranty. I think I'll try and replace the spark plugs this week, I'll also do a cooling system flush and throw a good ol' K+N airbox in for good measure

Hopefully the spark plugs can liven my car up again.

[philip1]

Do not put a k&n on this car unless you want AFM codes

[cr89x]

or the filter unless you like sandy oil.

[philip1]

K&N flow well because they only stop trees and boulders not dirt or sand.

On the cel I would have your coolant temp sensor checked I would also look at the wiring to it for stretching or breaks. P0128 is your coolant temp sensor so be vigilant of your levels.


Happy motoring.

[sashman15]

Are you guys saying an aftermarket K+N airbox in the stock housing is going to hurt my engine? How?

[cr89x]

Their tubing/airboxes are fine. They actually work and are well made. Their filters are very free flowing and do allow for power gains, but they have draw backs as stated. I knew a guy that did oil sample testing for years. He told me that he never tested a sample for an engine that ran a K&N air filter, no matter how well maintained or neglected, that did not have sand in it. That is why I discourage using one.

Plus, Phil has proven that on some cars, K&N air filters do not gain much power. He has found that factory airboxes with slightly improved plumbing and a decent drop in air filter shows the most potential.

[philip1]

I ran a k&n in my wagon for a while. It did two things well, fouled my air temp sensor and coated the inside of the pipe with dirt... Power wise it gained me nothing. Changing the air feed from behind the bumper to forward facing and 3" into the stock box and filter 9hp.... Something to think about.

[sashman15]

Aug 18, 2011 15:22:52 GMT -5 philip1 said:

I ran a k&n in my wagon for a while. It did two things well, fouled my air temp sensor and coated the inside of the pipe with dirt... Power wise it gained me nothing. Changing the air feed from behind the bumper to forward facing and 3" into the stock box and filter 9hp.... Something to think about.

Is there a known method to doing this in detail? It sounds interesting.

[philip1]

I can help on that