Car has a loss of power, hesitant

[Drew707]

EDIT:

Hey guys so my car lacks power especially at 40-60 mph. Intake gets really loud and im flooring it and my car still wont get up. When im at Wide open throttle my rpm gauge hesitates and i can feel and hear my car trying to gain power. i do not have a CEL though. im thinking something is wrong with my exhaust. Maybe no backpressure. i also have poor gas mileage. only got 265 miles on a full tank usually i get 350+ i need some more ideas what it can be just to be sure so i dont buy the wrong parts.


01 f23 automatic
recently changed oil
No muffler since it broke off
cat rattles at cold start up
Recently changed my spark plugs and cleaned my air filter
I do have dc sport header.

 

[jdmcg3]

Re: Car has a Rattling noise and poor gas mileage/powerloss

crawl up under there and have a look around for loose parts/hardware.

check to make sure you put the airfilter in right. maybe you put in upside down or didnt snap all the clips back on. and check to make sure you dont have a loose spark plug/s.

 

[RedRyder]

Re: Car has a Rattling noise and poor gas mileage/powerloss

Get under the car and look at things. Rattle could be the heat shield being knocked loose. Are you saying the CEL came on as a result of this bump? If so, could be an O2 sensor that got dislodged or bent from impact.

If the CEL has been on since the spark plug job you did, take them out again and check the gap, and make sure they're installed correctly. Which plugs did you use?

 

[Drew707]

Re: Car has a Rattling noise and poor gas mileage/powerloss

Get under the car and look at things. Rattle could be the heat shield being knocked loose. Are you saying the CEL came on as a result of this bump? If so, could be an O2 sensor that got dislodged or bent from impact.

If the CEL has been on since the spark plug job you did, take them out again and check the gap, and make sure they're installed correctly. Which plugs did you use?

The Cel was there before i changed my spark plugs,oil, air filter. the spark plugs i used were autolite copper. ill update when i get the cel from pepboys
Also i looked under the car and the rattling noise is coming from the inside of my catalytic. my friend told me to just hollow it out to get rid of the noise but im going to have to buy a new one anyway before my next Smog check.

 

[FunnyVictor86]

Re: Car has a Rattling noise and poor gas mileage/powerloss

The Cel was there before i changed my spark plugs,oil, air filter. the spark plugs i used were autolite copper. ill update when i get the cel from pepboys
Also i looked under the car and the rattling noise is coming from the inside of my catalytic. my friend told me to just hollow it out to get rid of the noise but im going to have to buy a new one anyway before my next Smog check.

Yup it's the catalytic converter.

 

[blacknight]

Re: Car has a Rattling noise and poor gas mileage/powerloss

Probably the cat has scraped.
Happened to me once

 

[Drew707]

Re: Car has a Rattling noise and poor gas mileage/powerloss

updated! help!

 

[twofast4u]

Re: Car has a Rattling noise and poor gas mileage/powerloss

with the dc sports header, doesnt that eliminate the primary 02 sensor? if so, that should effect gas mileage.

 

[J30MAN]

Re: Car has a Rattling noise and poor gas mileage/powerloss

I'm assuming before you had all that maintenance done you had a misfire which caused unburned gas to breakdown the inside of the cat which could be why it's rattling. That what happened to me. I need to change my catalytic converter soon so I don't hurt the engine.

 

[001Stunna]

Re: Car has a Rattling noise and poor gas mileage/powerloss

with the dc sports header, doesnt that eliminate the primary 02 sensor? if so, that should effect gas mileage.

It seems they just have it moved past the flexpipe, so you'd need to extend your wiring to there.

I'm assuming before you had all that maintenance done you had a misfire which caused unburned gas to breakdown the inside of the cat which could be why it's rattling. That what happened to me. I need to change my catalytic converter soon so I don't hurt the engine.

I don't think one misfire would ruin a cat.converter just in one shot though, unless the car kept dumping unburned fuel out of the exhaust. I'd say hollow out your cat.converter and see if things improve; if they do GREAT, that was your issue. If not check that your front o2 sensors is connected properly and wiring and plugs are all ok, check your sparkplugs are in properly and that the gap is ok, change your distributor cap and rotor, clean/check/change your air filter, run a bottle of injector cleaner in the tank. I'd say DO NOT seafoam through the vaccum lines unitl you have the cat.converter hollowed out first.