Engine bogging/stuttering

[truWarier02]

Recently, my car has been hesitant (stuttering, almost like it's going to stall) when I accelerate from a stop. Sometimes it would stutter a bit when I've slowed down on the highway and pressed on the accelerator again to get up to speed. The RPM needle would fluctuate back and forth slightly before 2k rpm as this is happening and eventually smooth out through the rest of the powerband. Start-up and idle is fine, no problems. NO CEL.

Two weeks ago I swapped OEM and SRI back and forth to do SMOG but I doubt that has anything to do with it. I decided to check my K&N panel filter yesterday and it was nasty. So I cleaned/oiled it and got it back to looking almost new. I thought that would've fixed the issue but the problem still exists.

Today as I pulled up to a parking space, I decided to put it in neutral and rev a bit and it still chokes at the beginning of the rev but at the end of the rev, I stook my head out and noticed a metal rattling sound (failing cat?)

Any input/experiences would be appreciated. This is making my car feel like an absolutely bucket.

 

[kn0x47]

yup its probably your cat. pull the O2 sensor out and turn it back on and see how it runs

 

[kn0x47]

i would think the check engine light would be on tho if it was the cat

 

[001Stunna]

A bad/clogged converter can very well make the car be sluggish.

Do you have access to a live scanner...or a bluetooth obd2 plugin and torque app? Check what your front and rear o2 sensors are reporting.

Checked things like sparkplugs to make sure all is good in there?

Have someone revv the car slightly and feel for pressure at the tail pipe and see if it seems off/puffing etc.

 

[DarkSideAccord]

sounds like a clogged cat

if it gets worse, tht's most likely the culprit.. it'll come to a point when the car won't even start up anymore

 

[agginline86]

probably not the secondary o2, as only the primary o2 sensor affects the idle
if I'm not mistaken
i would check primary o2 and the rattling from a bad cat is annoying as hell. i feel your pain. i temporarily replaced my cat with a test pipe. no thanks to catalytic converters being so damn expensive here in cali

 

[truWarier02]

Actually I don't hear anything from the cat area now and aside from accelerating from a stop, the transmission is smooth.

But what I discovered today while driving was interesting. If I am at a stop, release brake pedal and let the car roll a feet or so and then feather the gas pedal until around 2k rpm, the problem (bogging/misfire) does not occur. But if I try to release the brake pedal and immediately give it gas, it'll slightly stutter.

I even had a shop mechanic ride in the car with me earlier and he was able to notice it. He's thinking maybe spark plugs/wires. Wires are original and spark plugs were last replaced back in 2007 with 90k miles, my car has 161k miles now. And there's some oil buildup around the distributor cap as well. I'm gonna get some NGK spark plugs and wires and change the cap & rotor too.

And I appreciate the suggestions guys.

 

[truWarier02]

Update: Replaced my old Bosch spark plugs and wires with NGK and changed distributor cap & rotor. What a difference. Idle and acceleration are smooth. Feels like I gained some power back. The automatic downshifts are silky smooth rather than sudden drops. It solved my acceleration stuttering issue.

 

[H-town_Ryda_06]

Hey my car has been doing this exact same thing.

I have been trying to figure it out since I just did a full tune up and I have a new high flow cat all done maybe 4 months ago, but this has only been happening to me for about 2 months. Also it only happens sporadically for me, sometimes every day sometimes once a week.

My cap and rotor are new but I will open it up and check it since u say that was the issue for yourself

 

[truWarier02]

Hey my car has been doing this exact same thing.

I have been trying to figure it out since I just did a full tune up and I have a new high flow cat all done maybe 4 months ago, but this has only been happening to me for about 2 months. Also it only happens sporadically for me, sometimes every day sometimes once a week.

My cap and rotor are new but I will open it up and check it since u say that was the issue for yourself

It was definitely a weird issue. One day it'll occur on most acceleration-from-a-stop and the next day, it'll happen once or not at all. Do you have new spark plugs and wires too?