Engine Misfire/exhaust Problem
 

Hey, I've been a member at these forums for a while but haven't been on in a long time. Recently I took off the catts on my car. My car never had the the check engine light go on and the exhaust sounds good. Recently I've been getting randomd check engine pop ups and the check engine light would starting flashing rapidly. I read the manual and it said that this happens when you have engine misfire. Whenever this light goes on my exhaust changes its note and it starts to get really choppy and I can definately feel a loss of power above 2k rpms and acceleration is very weak and choppy too. Has anyone ever had this happen??

=(

My truck started missing one day and then the Check engine light started flashing. Plugged in the scanner and cylinder number 5 was missfiring. A plug changed was all that was needed in my case. If its missing, your not running on all 8 cylinders, thus its going to run real rough and have a loss of power. Plug in a scan tool if you have one or goto Autozone and have them plug in to see which cylinders are missfiring or see if any other codes show up.

The most likely cuplrit is that your SES is flashing because the O2 sensors are detecting a condition that shows that the cats might be getting damaged. The SES always flashes when this occurs.

The fact that you no longer have cats, but still the rear O2 sensors could certainly explain this. When you remove the cats, you need to turn-off this O2 sensors. Remember, you have no cats, but the car still thinks they are on, right?

To make sure you don't have a serious problem, avoid driving the car and get the codes read. As a flashing SES could mean a serious problem such as a missfire or worse, but I suspect it is just as I explained above.

oops, I just re-read your post. Sorry. Sounds like you definately have a missfire situation. I would suspect a bad coil pack or plug. The fact that the light flashes, I would say it is a plug. For some reason, the SES on these cars don't seem to flash when it is a bad coil pack, but a bad coil would cause the same condition.

I have had this same exact situation with my car.

Have you recently gotten water under he hood?

I don't think any water has gone under the hood but i will definately go and get my car checked out at a local autozone. Thanks guys! I will give a follow-up on conditions after i get it checked.

if it is missfire...what would i have to get replaced? sparkplugs? cylinders?

A missfire is simply when a cylinder does not fire. When you run on only 7 cyclinders, it will run like total crap. It will be choppy and have no power.

When you have one, this means you either lack fuel or spark to get ignition.

So, you could have a bad or plugged fuel injecotor, a bad spark plug, or a bad coil pack. You could also have a plugged fuel filter too.

I would be more suspicious of a coil pack or a plug and I would bet on a coil pack.

Hopefully, the SES will correspond to a specific cyclinder. When I get these dam problems, I always have to figure it out on my own, cuz the last time the SES did not come one.

If you want, you could just replace all your plugs. Takes about 1 - 2 hours and is cheap for parts. If you have high miles, this is not a bad thing to do anyway. BUT, have the code read first before you destroy the evidence.

I did have a situation on my car, where replacing the plugs was only a temp fix and the missfire came back after a few months. Turned out it was a bad coil in the end (actually two were bad).

You can also have all your coils removed and load tested on a bench to find a bad one.

Coil packs cost about $40 each.

Again, the fact that it does not missfire until you or under load at that rpm, only points in the direction of a bad coil. Seems like it is giving up under load or arching when is send the spark to ground rather then to the plug.

i replaced a coil pack in my car and it is doing it again.i had it put on two computers one sayed that i have a air leak and the other sayed my fuel pump is going out.it runs good until you stop at a stop sign or if it is ideling.what could it be please help me