2005 impala 4t65e transmission

09-13-2016, 10:42 AM
I have been researching like crazy to find a solution, I stumbled upon this and I hope someone can help. When I first bought the car it was sluggish to drive. I replaced the catalytic converter, new plugs, wires, fuel filter, and replaced the air filter with a spectra aftermarket air filter. After i test drove it and it was a night and day difference. The car drove way better.

I took it to a local transmission shop and they had it for days the only thing they could come up with is a p1811 code. The thing is there is no check engine light on at all. The light works i know it does.

My symptoms are Driving uphill is a pain I will be cruising at 60 mph and once I start going uphill the mph goes down to about 40 and I have to really give it gas to make it go. Regular driving on a flat surace is slightly diffI cult but once past 30 it drives like a dream. The previous owner did a BG transmission flush and changed the trans filter aswell. I have a shift kit in the garage, and I have been thinking of adding some lucas or seafoam trans tune. What do yall think? :runaround:

09-13-2016, 04:32 PM
Why do think the trans is causing a lack of power? 1811 refers to the pcm sensing some trans pressure,/shifting issue and commands the system to go to full line pressure. This would cause hard shifting, but not affect power as you describe.

09-13-2016, 09:43 PM
Thank you for your feedback. The engine seems fine, of course I don't have the funds or space to dig into it. I'm just grasping at straws at this point. It has 170k on it but so far it's been a great car.

j cAT
09-17-2016, 08:23 AM
these pre 2006 GM vehicles now require dexron VI NOT dexron III !!!! also your vehicle and other model years had defective cat converters. what could be wrong is the engine has an intake leak too lean also dirty fuel injectors. does the transmission properly down shift when on hywy speeds ? it may stay in over drive and not drop out causing a drop in speed. you never have a GM transmission flushed this is damaging to the torque converter . the method to use is the FLUID EXCHANGE METHOD . THIS TAKES MORE TIME BUT NO DAMAGE.....

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