Engine low power?

We drilled a hole in the exhaust pipe infront of the CC. Once we did that I started to get more power back. I guess I will have to replace it now.

My car start and run good but, it has no power

My car runs fine in park once in gear and going down street it bogs down I replace the front set of wire and plugs because it was reading misfire in 3, a mechanic down the street took it for a test drive and came back and stated the engine was bad and needed to be replace, how did he determine this when all he did was drive around the block, the engine make no noise it just seems to be starving for air or bogging down. What could be wrong or is he right and does it need an engine.

Yesterday, I started to drive up a steep hill. The engine pulled down real hard and would not hardly pull up the hill. It didn't appear to be missing out. As far as all cylinders firing, it seemed to be ok on that part. If I put the accelerator all the way down on the hill it would shift down to low gear and the engine was accelerating as if I had shift the transmission to low gear manually while driving fast. The engine seems not to have the power it had when I got it. If I drive it on any other kind of terain, the engine seems to run good. What could cause this problem?

My car is very slow to pick up speed when accelerating it kinda jerks and stalls. The check engine light comes on every once and a while, stays on for about a day and then goes back out. I think it may be my fuel injector because I am burning up gas a lot quicker than before. What do I need to do in order to clean it? Thank you for your help

I had it scanned and P0300, P0125 and P0404 were the codes that came up but the light does not stay on. Thanks

How much does one of those run and how intensive is the work to put it on?

Hey Joe,
So I could go buy the part and have someone put it in for me and that should fix my problem?

My wife has a 2003 chevy impala and was having the same problem with the slow acceleration. To make a long story short the problem was the cat converter. And the car only had a little over 80k miles on it. Well its all fixed now and runs great. And for the P0125 code it could also be the thermostat instead of the temp sensor. Both parts are going to be under $15 each. I am going to replace the thermostat 1st and go from there. If that isn't it then I will replace the temp sensor.

I'll try to explain the issue as completely as I can.

First of all, no DTC codes at all.

The vehicle starts and idles fine. Upon startup there's a loud sucking noise coming from the airbox before the filter, which I know is normal because of the IAC during cold startup. At any point in neutral or park, cold or hot, the engine sounds fantastic, has great throttle response and revs up nice all the way to the limiter. I've replaced all the plugs, wires, and coils. I did a compression test when the plugs were out and it came out to 167-175 for all cylinders. Every plug looked fantastic, nice tan color, no fouling. Beautiful.

If I start driving right away immediately after I start the vehicle, it accelerates through the gears and shifts smooth with what I would call normal acceleration. Feels like it should and if I could get it to stay that way, I'd be happy. However, after a couple of blocks, (or if I let the engine idle for a couple minutes before driving) the acceleration becomes very poor. There is a more hollow muffled sounding sucking noise (not even sure it's air, but that's the best way I can describe it.) During the poor acceleration. It seems to shift though the gears still, it just takes forever to get up to a speed to get the gears to shift. I'm actually not sure if it's even starting out in the proper gear. It doesn't slip during this, it's just like pressing the gas and it accelerates super slowly, there's no high rpm's as you would see in slipping.

If I press the accelerator maybe 2/3 of the way down so that it drops down a gear, the engine revs higher, the hollow sound goes away and it sounds more like it should. It accelerates much better, but I'm still not sure it's as good as it should be.

If I floor it so it drops down another gear, engine RPM's go way higher, but zero acceleration (transmission is slipping) with a loud rattling like marbles in a tin can. This rattling is worse the more the car is driven (or warms up I guess).

Originally, I suspected the cat, but I'm not sure why it would be okay for the first couple blocks before it warms up. Also, in neutral, the engine sounds awesome with great response. Because of this, I"m beginning to think it's not a plugged cat. Even if it was clogging up after coming to temperature, it would be bad at idle too, I'm thinking. I'm also ruling out fuel delivery as it revs up great and very responsive. I haven't checked the rail pressure.

If I stop the vehicle and let it sit for a few minutes, then start it up and drive again, again it's good for a couple blocks and then starts doing the same thing again.

Would doing a transmission fluid and filter change (not flush) fix this? I'm thinking that there's some kind of restriction someplace that clears as the transmission fluid drains and then clogs up soon after starting the vehicle again. The fluid level is correct and the fluid isn't black, but it isn't red either. I'm confused because it seems so great for the first couple of blocks and when it starts having low power, it's not slipping until you floor it, it just bogs down under normal acceleration. If it's the PC solenoid, why does it take a couple blocks to see the problem?

Another question. Will pulling the front O2 sensor allow enough air through the port to allow me to diagnose the catalytic converter? I don't really feel like disconnecting the whole pipe or manifold before the catalytic converter.

I plan to clean the MAF sensor, but looking at the readings on my OBD tool, the numbers don't seem out of line and there is no DTC and the engine seems to be running fine.

Any help would be truly appreciated. Thanks in advance.

Hi Joe, thank you for your reply! No I haven’t ruled out the catalytic converter at all, I’m just really confused as it idles and revs up so nice when it’s not in gear. The throttle response is so good when it’s not moving.

The confusing thing for me is the fact that it drives great for two blocks after startup. Plus the fact that when it is having poor acceleration it doesn’t act like the transmission is slipping at all really until you floor it. It’s mostly just bogging down.

It’s frustrating because half the symptoms seem to be bad catalytic converter and the other half are transmission.

I would have pulled the O2 sensor already but I hurt my back last week so I’ve been taking it easy. I hope to get back to it this weekend.

Thanks again for your reply. I’m hoping you’re right.

Took the O2 sensor out and went for a test drive. It ran much much better. Accelerated up through the gears just fine. Still not 100% but I’m sure it will be once I get the cat replaced.

Definitely the catalytic converter. Pricey but much better than a transmission!