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Chevy Impala dawgging when gas pedal is pressed

Bought a 2003 impala recently and all has been great, but most recently there just is no power and when you press on the gas it boggs down lifters rattle and no forward thrust. check engine light starts flashing and if you find the sweet spot you can ease it up to speep. Fuel filter clogg? new pumb needed? or worse trans problems
car has 161,000 miles



Have you gone through the engine compartment and checked the basics, like the air filter, fluid levels and such? Start with those, and let us know what happens. Have the fuel components ever been cleaned? It’s not a terribly tough job to do in the driveway, and almost anyone that can change brake pads can do it.

This sounds like an air/fuel issue more than anything else, and not a tranny problem. I don’t think it’s a fuel pump problem, either, as I don’t think it would ever get far past idle (if it ran at all) with a dodgy fuel pump.

Let us know which motor you have, too. There are 2 6’s available on that one…the 3.4 and the 3.8 OHV.

This is most likely ignition related. Have you checked the spark plugs? They may be original equipment and badly worn. Another possibility is a bad coil or ignition module. Sometimes those coils will develop a carbon track, causing a hit-and-miss misfire, which is why the check engine light is flashing. A distant possibility is a plugged catalytic converter, which is fairly common on these cars with the 3.8L (much less common with the 3.4L), but will usually just cause very limited top speed (sometimes as low as 15 mph) and for the upper plenum to melt if the issue is not addressed in a timely manner.

If the check-engine light is on, then you should have the codes read instead of guessing at problems.

I hope you’re not driving the car with the check-engine light flashing. That means engine damage may be occurring.

check engine light went from flashing to on full after a quick spin. will let all know. it’s beyond me. thanks

As @lion9car said, get the check engine codes read. They do it for free at Autozone or O’reilly’s (and probably others) in an effort to sell you the parts needed to fix it yourself.

Just returned from dealer.
cat converter clogged.
Intake manifold gasket to be replaced
tune up
coolant flush
It’s here at home awaiting the money tree to grow.

Local muffler shop can install a converter for much less than a dealer and online places like Jegs and Summit sell high flow catalytic converter types for around $90 claiming 50 state legal…

Intake manifolds are not too difficult but an independant mechanic would be much cheaper than the dealer… Tune-up is plug change and maybe air filter and fuel filter in today’s world… Coolant flush would be mostly done when changing the intake gaskets anyway…

Try some local independent shops or perhaps even the muffler shop as suggested (many of those guys have done dozens of these intake gasket jobs as it’s a very common, routine thing). Your estimate from the dealer seems about a grand higher than it should be for all this work. A direct fit converter should be no higher than $400-500 installed as I recall, unless you are in CA, then it’s more. Intake gaskets are pricey to do because they take about six hours to replace. Most decent shops should be willing to install spark plugs and wires with the intake gaskets for another half hour labor rather than full book time since they are very easy to replace when the engine is apart (this is what I used to do). The coolant flush doesn’t necessarily have to be done unless they indicated your cooling system has been neglected. The coolant has to be drained to replace the intake gaskets anyway, so unless the system has been neglected, refilling with fresh should do.

You still didn’t say which engine your car has, but all of the above is applicable to either engine. If you have the 3.8L, however, whoever does this work needs to check the upper plenum for damage. The EGR tube passes through the upper plenum, which is made of plastic, and the excessive EGR flow that is caused by the converter being plugged can cause enough heat to melt the plenum. This is not a concern with the 3.4L as the upper plenum is aluminum.