tonight i lost acceleration in my car & my check engine light came on. i was able to coast to an exit. my car starts up and when i rev the engine the car is fine but when i let off the gas it acts like it wants to die. there is also a strong odor of gas. any thoughts?

Find out why the check engine light is on first. Take it to auto zone so they can scan it. It will probably be something about a misfire or catalyst efficiency.

When you smell gas from inside the car please beware of fire. There is no reason whatsoever you should ever detect gasoline odor, other than that, listen to John.

Sounds like an O2 sensor. An OBD2 scan will say for sure. Most parts stores do them for free.

O2 sensor wont cause you to loose acceleration.

You are wrong John. Here is a 101 on the basics of fuel management in Most ECU's. This is not my writing, but correct not the less...... Every internal combustion engine requires a certain mixture of air and fuel to operate correctly. Through years of research and development, auto manufacturers decided that this optimum ratio is 14.7 to 1 for stock applications. That means that for every 14.7 parts of air the engine takes in, there must be 1 part fuel for the engine to perform at its best. Less fuel creates a lean condition; more fuel creates a rich condition. A lean condition gives a bit more power, but also results in massive heat accumulation. A rich condition robs the engine of power, but results in cooler running temperatures. If the engine is too far off in either direction, the vehicle might not be able to pass an emissions test and might not run well. Rich Conditions If the oxygen sensor goes bad and tells the computer that the engine needs more fuel when it in fact does not, the vehicle will run rich. Telltale signs of a rich-running engine are a noticeable odor of gasoline coming from the tailpipe, erratic idle, fouled spark plugs and the aforementioned loss of power. Although the computer actually does all the air and fuel adjustments, it is the oxygen sensor's job to tell it which way to go. Since a rich condition robs a vehicle of power, a bad oxygen sensor can cause poor acceleration. If your vehicle is running rich, replace the oxygen sensor to see if that solves the problem. Another Possible Issue While the oxygen sensor can indeed cause an engine to run poorly, slow acceleration could also be a clogged catalytic converter, or CAT. The CAT is located further down the exhaust pipe from the oxygen sensor. Its job is to superheat the exhaust fumes before they reach the tailpipe, so that the result is cleaner emissions. Over time they clog up and cease to work properly, which can result in poor acceleration, an erratic idle and failed emissions tests. In a new, clean-burning engine, the CAT will perform effortlessly and do its job. However, if the oxygen sensor goes bad, which may result in more emissions, the CAT can fail prematurely, so the two problems can actually run hand in hand. Read more: How Can a Bad Oxygen Sensor Cause Poor Acceleration? | eHow.com http://www.ehow.com/how-does_4898092_oxygen-sensor-cause- poor-acceleration.html#ixzz2DX7RHEmd

That is the difference between "CAN" and "Won't"

I agree with the results that have been given but it seems the no one hass touched on th possibility of a fuel leak. Its dangerous but u will need to have ur vehicle run for 5 min in a well ventelated area after the 5 min turn off ur car and check for fuel drops on the ground and check all fuel lines make sure to check the fuel filter chevys have a bad track record for crap fuel filters they dont last nearl as long as dodge honda or acura. Best of luck

Most certainly right on an OBD1 vehicle but here is the beauty of an OBD2. http://www.ehow.com/ about_5844954_signs-symptoms- o2-sensor-failure_.html. delete the spaces... 2 things are required for an ECM to go into closed loop mode. 1 engine is up to operating temp and 2 the oxygen sensor has to be heated and fluctuating from -.5 to +.5 volts if those two don't meet requirements then the vehicle stays in open loop and burns a little extra gas and it will run the same way it runs when the car is first started up "cold". If a vehicles O2 sensor tends to show a condition where it stays a little richer or a little leaner then the short term fuel trim will attempt to compensate for that. If that short term fuel trim seems to do the trick then the vehicle will store it as the long term and begin using that as default for closed loop. If the short term ends up too far off from the long term then it will set a code for the O2 sensor and disable readings from it until the next time it goes into closed loop. A failed O2 sensor will trip codes such as catalyst efficiency monitor, O2 sensor lean, O2 sensor rich O2 sensor low voltage. When any of these codes are tripped the vehicle automatically goes into open loop mode and stays there until the O2 sensor begins to behave properly. I live in lake county Indiana where our emissions testing is just as strict as California thanks to all the steel mills located on lake Michigan.

Its a WIK fuel filter. Try to find a better one!!!

fuel pressure regulator leaking and the vacume is sucking fuell into engine making it smell and die