Hey all..I bought my 01 silverado about 4 months ago and I have since then put on about 7k on it..Other than the common Inter steer shaft and driveline clunk I am happy with it so far.Anyway When I bought the truck it had gobs of power it was very impressive.I brought the truck in for service 2 weeks after I bought it for 4x4 switch and lube steering shaft and slip yoke and since then I have noticed a decrease in power.It seems as though the truck lost horsepower and throttle responce .I called the dealer and they declined flashing the pcm and said that they did nothing that would cause the different performance....2weeks layer I brought it back for inner front end work and an alignment .And since then the truck is ok other than this weird power loss..I have since the last dealer visit changed to synthetic oil changed tranny fluid filter. diff fluids. t-case fluid. New throttle body gasket .new spark plugs .new fuel filter .air filter.I pulled the tb and cleaned the IAC and all the carbon out.Amnd I still have power loss.It has been about 3 months and now it is very sluggish and shifts harshly 1-2 and has a rough idle. It is not throwing any codes..What would cause these symptoms??? My fuel pressure reg is good and I checked Egr cleaned MAF and ran some techron chevron fuel inj cleaner and it has smoothed the idle but is still a sluggish pig.WTF ..I even contacted the PO to see if he had a comp tune on it .and he said he kept it stock .So that eliminates a custom tune that was flashed..What else could it be????????????? 2001 CHEVY SLIVERADO ECSB 4X4 5.3 auto... 55K

 

reach down and pull the parking brake lever. J/K

 

first of all what are you comparing your loss of power to? is there a certain road that you start from a stop and get up to a certain speed at a certain point.

it is hard to judge if you lost power. unless, of course we are talking about the truck just not wanting to move out of it's own way now and before it would just haul ***.

almost everyone gets used to the amount of power they have and get comfortable with it. after a while, it just isn't the same because we are used to it.

if none of that seems to fit your problem, i would check the cats to make sure they aren't clogged up. 55K i wouldn't think so but it is a possibility.

hope this all makes sense and helps you out

 

when i first got my truck same thing course i went from an import to my truck so the difference was huge and after i got used to it, it just didnt seem as fast so then i started modding

 

The truck has flowmasters on it and the very first thing I noticed when I drove from the dealer was that the exhaust sounded different and that the tranny shift points were not as tight as before..It seems as though the truck has some kind of blockage holding up power .The first day I bought it I climbed the hill next to my house with a trailer full of drywall and it had mondo power climbing it..After the dealer visit going up the same hill it just outright pooches it..I know that I may sound crazy and I do agree that we all get used to the power in our trucks but the difference is litterally night and day.When I first test drove it I would have sworn it had a custom tune .The throttle responce was incredible and it plain hauled ***.After the dealer visit it is just not the same...Could this be a bad TPS and at 55k how would I tell if I have plugged cats??I have been scrathing my head on this one. I wonder if the dealer somehow tampered with it or beat the hell out of it on a test drive that may have messed something up??Today I will try to run some seafoam through it and change the oil ..Hopefully I can figure this out.I also read here a while back that when a computer is flashed that there is a stubborn slowness that follows.This is what I believe I am experiencing.For example When I first bought it it would light up the rear meats with almost no effort.Now it barely chirps them at half throttle????And it seems that at around 45 mph it wont downshift and it will take alot of throttle input to downshift and start moving?????Any help is greatly appreciated..I dread having to go back to the dealer for anything now they pretty much gave me the complete runaround and deny everything.And each time I brought it in I got new scratces and dings and road chips ..I may have pissed them off because I brought in the tsb.for the steering shaft and nickle plated slip yoke..Maybe they are getting back at me by tampering with my truck..But waht could they have done..This is driving me crazy..They tried to put off any service till the 60 day dealer warranty was up by giving me poor excuses and just plain dicking me around. WTF .........................

 

my truck was doing something similar and I changed out the spark plugs and spark plug wires and cleaned all the fuel injectors, but I think the main problem was the spark splug wires and mine only had 65k miles.....???

 

Maybe when you bought it it had a tune, and when you took it to the dealer they reflashed the ECU?

 

If there is a software upgrade that fixes a '01 tranny 2-3 shift, for instance, and when they had your truck they upgraded the PCM so you get this tranny fix, your entire PCM will be overwritten with a stock '01 Silverado PCM tune. So if you had a Superchips or custom tune and the dealer performed a fix like this, you have lost your tune. This could be your issue.

Do you know the previous owner? Can you contact them to find out?

 

I did speak to the po and he is an older gentleman and he told me that he left the truck stock other than the flowmaster exhust? I bought a new TPS and ran some seafoam through it and it did open her up a bit.The exhaust sounds crisper and it revs great. So the seafoam did help a bit..I am going to buy new wires next to see if that is the problem..Thanks you guys for the input and help..Could exessive carbon build up do this ?? Should I run more seafoam through it?That stuff kicks *** You should of seen the carbon smoke come out of the exhaust .I could not believe that there was that much carbon buildup at 55k..And I noticed that it shifts much smoother now also..I think the new TPS will help also................Now I'm off to the store to buy $75 spark plug wires was the cheapest I could find...

 

Did you fill up on gas after the visit to the dealer? Maybe you got a load of crappy winter gas.