Impala high pitch whistle when step on gas

2002 impala 3.4

Bought a car, has a vacuum leak somewhere behind the engine near firewall. I have next to nothing for power. Slight hills drop my speed drastically to the point I need to toss my hazards on to get people to go around me. Example, yesterday was going 60km and got to a hill, halfway up I was going about 35km. The engine then kicks up the rpm but I still drop speed, temperature goes up, and once back on level ground temp drops fast.

If I'm driving even on level ground if I were to put the pedal to the floor, the engine reacts but no change in speed. Any time that I have my foot on the accelerator you can hear a whistle which gets very high pitch (and very very loud) going up hills.

A friend thinks it could be my EGR. any thoughts?

2002 impala 3.4

Bought a car, has a vacuum leak somewhere behind the engine near firewall. I have next to nothing for power. Slight hills drop my speed drastically to the point I need to toss my hazards on to get people to go around me. Example, yesterday was going 60km and got to a hill, halfway up I was going about 35km. The engine then kicks up the rpm but I still drop speed, temperature goes up, and once back on level ground temp drops fast.

If I'm driving even on level ground if I were to put the pedal to the floor, the engine reacts but no change in speed. Any time that I have my foot on the accelerator you can hear a whistle which gets very high pitch (and very very loud) going up hills.

A friend thinks it could be my EGR. any thoughts?


put your hand behind the tailpipe to feel how much flow you have coming
out. may be a clog in the system

If you think the exhaust is clogged ...remove your OX sensor(s) on the exhaust manifold(s) and see if the car has more power. the ox sensors are fragile.

what if you pop the hood and start the car in park and rev the engine, do you hear the whistle?

Thanks for the replies. I've been AFK for a bit. Sorry!!!

I checked the exhaust, and it is certainly less than it should be for pressure.

I've taken a couple more videos, and yes, when I rev the whistle is there as well.

http://www.youtube.com/watch?v=qJLaC26G0m8

http://www.youtube.com/watch?v=6VtBc0acR-E

I had a truck with the same " no power " symptom as you described as well as the engine temperature going up when under a load . I tried many things before finally replacing the catalytic converter .It had the 49 state required converter as well as the California required converter . The " guts " of the front converter had disintegrated and had migrated into the California required converter stopping it almost completely up . After the replacement , the difference in power was almost unbelievable ! I suggest having the converter checked for a similar condition - good luck !

as has been suggested remove the O2 sensors and with the holes open test drive...if the power returns your exhaust is plugged....could be cat converter and muffler...


your vehicle was built with defective GM cat converters !

I will check that out and see! Thanks

And the O2 sensor is in a spot that makes it near impossible to get at with a cresent wrench. Is there a special tool I'm supposed to use or just a wrench?

You need an O2 sensor socket to make it easier. You will then be able to get an extension and ratchet on it to R&R. Also how many miles on the car? Last time a tune up was done? W bodies have been known to have issues with cats plugging but you also need to makesure the engine is running properly. A rich running engine will overheat the cat and cause it to burn and plug again. If it is the cat that is plugged it sounds like the whistle is from excessive backpressure and caused the hot exhaust to melt something, possibly the EGR valve or upper intake. I have seen this happen as well as engines catching fire due the heat that can build up due to restricted exhaust.

Edit just reread your post and sine you have the 3.4 no need to worry about the upper intake melting. Its aluminum. Could still have other exhaust leaks though.

I have done this before, in some cases the small amount that escapes from the O2 sensor hole is not enough, I have had to actually open the exhaust to get the result. If you separate the flange at the exhaust manifold it will provide a better test result but dont forget to wire the exhaust up before a test drive so it does not hit the ground. and on a note, this sounds exactly like the cat is plugged I agree .

Try this:

From a dead stop, LIGHTLY ACCELERATE up to 50 mph.....does the car shift and slowly get up to speed?

now, from a dead stop, LAY INTO THE ACCELERATOR PEDAL.......Does the car bog down, not shift, and not rev higher than 3K rpms?

If yes to both, bad cat.....sound you are hearing is probably back pressure coming out of the exhaust manifold doughnut seal....

If it is the cat, it's usually only 8years/80K miles......but thought I read somewhere, where they may have increased this.....if they did, there is a TSB on it.....

Googled this, and came up with, The special policy number 05551 ......10/120K.....go to your local Chevy dealer and ask for a copy of 05551, and see if your vehicle's VIN applies to this.....if it does the cat is covered....

"Some customers of 2001-02 Chevrolet Impala, Monte Carlo; Pontiac Grand Prix; and Buick Regal model vehicles, equipped with a 3.4L (RPO LA1 - VIN E) or 3.8L (RPO L36 - VIN K) V6 engine, may experience a condition where the vehicle exhaust catalytic converter is replaced due to complaints of lack of power or illumination of the Malfunction Indicator Lamp (MIL). This may be due to the front endcone insulation from the catalytic converter breaking away and blocking the front of the first catalyst brick and preventing the free flow of exhaust gas through the converter."

Involved are all 2001-02 Chevrolet Impala, Monte Carlo; Pontiac Grand Prix; Buick Regal model vehicles, equipped with a 3.4L (RPO LA1 - VIN E) or 3.8L (RPO L36 - VIN K) V6 engine and built with the VIN breakpoints shown:
2002 Chevrolet Impala 29100001 - 29374833
Source(s):

Special Policy Adjustment - Catalytic Converter # 05551 - (Sep 14, 2005)


Or call GM customer Service, and ask them to look up the special policy number 05551, and give them the VIN, to see if you qualify....

You need an O2 sensor socket to make it easier. You will then be able to get an extension and ratchet on it to R&R. Also how many miles on the car? Last time a tune up was done? W bodies have been known to have issues with cats plugging but you also need to makesure the engine is running properly. A rich running engine will overheat the cat and cause it to burn and plug again. If it is the cat that is plugged it sounds like the whistle is from excessive backpressure and caused the hot exhaust to melt something, possibly the EGR valve or upper intake. I have seen this happen as well as engines catching fire due the heat that can build up due to restricted exhaust.

Edit just reread your post and sine you have the 3.4 no need to worry about the upper intake melting. Its aluminum. Could still have other exhaust leaks though.

I disagree with your idea of the O2 hole not being large enough to trouble shoot this , to test out for an exhaust restriction..

this is a small low powered engine that O2 hole will make a noticeable difference in exhaust back pressure reduction to allow for the engine to operate with more power...might not be 100% but very noticable increase in power !

you mess with exhaust flanges that can turn into an expensive unnecessary process..

with a larger V8 with a heavy vehicle this is more possible..

I disagree with your idea of the O2 hole not being large enough to trouble shoot this , to test out for an exhaust restriction..

this is a small low powered engine that O2 hole will make a noticeable difference in exhaust back pressure reduction to allow for the engine to operate with more power...might not be 100% but very noticable increase in power !

you mess with exhaust flanges that can turn into an expensive unnecessary process..

with a larger V8 with a heavy vehicle this is more possible..



I hope u misquoted another poster. I would never remove the O2 sensor and then see if the engine runs better I would connect a pressure gauge and measure exactly how much backpressure I have. But for the shade tree guy (not talking you, jCat) it may work to run with O2 sensor out.

Sent from my Droid X. Typos probable.

I hope u misquoted another poster. I would never remove the O2 sensor and then see if the engine runs better I would connect a pressure gauge and measure exactly how much backpressure I have. But for the shade tree guy (not talking you, jCat) it may work to run with O2 sensor out.

Sent from my Droid X. Typos probable.

with no test guages/correct threads/hoses available this is used quite often in the back yard mechanics world ...very fast , no guessing...removal of the sensor for a 5 min run quickly reveals the exhaust being plugged...

many members have had no issues with this proceedure...especially this vehicle...!

I am not the one that said what you originally quoted. I simply stated how I do it.

Sent from my Droid X. Typos probable.

I am not the one that said what you originally quoted. I simply stated how I do it.

Sent from my Droid X. Typos probable.

If you have all the proper test equipment at hand you would do it with the test equipment like you do...That would be another way to properly diagnose this.

most asking about this obviously do not have any test equipment..

A plugged exhaust with just a small amount engine work experience is not that complex..to figure out ...

I also use a vacuum guage to check out problems with the original poster issues....having that knowledge to interpret the readings is a very cheap but though way of seeing whats wrong with the engine..

It would be great if he posts back what he did and how the issue was resolved...

Try this:

From a dead stop, LIGHTLY ACCELERATE up to 50 mph.....does the car shift and slowly get up to speed? Very slowly. lol Up a *slight* hill, I don't get past 30.

now, from a dead stop, LAY INTO THE ACCELERATOR PEDAL.......Does the car bog down, not shift, and not rev higher than 3K rpms? Bogs down, engine revs high but very little for acceleration.

Googled this, and came up with, The special policy number 05551 ......10/120K.....go to your local Chevy dealer and ask for a copy of 05551, and see if your vehicle's VIN applies to this.....if it does the cat is covered....

"Some customers of 2001-02 Chevrolet Impala, Monte Carlo; Pontiac Grand Prix; and Buick Regal model vehicles, equipped with a 3.4L (RPO LA1 - VIN E) or 3.8L (RPO L36 - VIN K) V6 engine, may experience a condition where the vehicle exhaust catalytic converter is replaced due to complaints of lack of power or illumination of the Malfunction Indicator Lamp (MIL). This may be due to the front endcone insulation from the catalytic converter breaking away and blocking the front of the first catalyst brick and preventing the free flow of exhaust gas through the converter."

Involved are all 2001-02 Chevrolet Impala, Monte Carlo; Pontiac Grand Prix; Buick Regal model vehicles, equipped with a 3.4L (RPO LA1 - VIN E) or 3.8L (RPO L36 - VIN K) V6 engine and built with the VIN breakpoints shown:
2002 Chevrolet Impala 29100001 - 29374833
Source(s):

Special Policy Adjustment - Catalytic Converter # 05551 - (Sep 14, 2005)


Or call GM customer Service, and ask them to look up the special policy number 05551, and give them the VIN, to see if you qualify....

Awesome, thank you! My last digits of my VIN start with 291xxxxx so I'll be calling today to see if I am covered!

Ugh... Fail....

This special policy covers the condition described above for a period of 10 years or 120,000 miles (190,000 km),whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership.I'm at 266,000km....:crying:

So.... Now need to figure out replacement?

[EDIT]: I figured wouldn't hurt to contact them anyways, just in case. Can make the case that this is actually my first Chevy. Maybe they'll be nice. lol

Ugh... Fail....

I'm at 266,000km....:crying:

So.... Now need to figure out replacement?

[EDIT]: I figured wouldn't hurt to contact them anyways, just in case. Can make the case that this is actually my first Chevy. Maybe they'll be nice. lol


have the muffler shop drop the exhaust and make sure that the muffler has no cat pieces stuck in there ! I would replace the whole exhaust if it is in fair to bad condition...

Like was mentioned before ...before replacing any converter make sure the fuel management system is working and the the ignition system is producing a strong spark..to new correct spark plugs ...wires can mess this up...