Wide open throttle problem?

[98talondb]

When my car hits 4000rpms it just feels slow at wide open throttle I can punch it at 3000 rpms and itll run hard as soon as it hits 4000 and above it wont gain speed or power. If I down shift it still has problems. Idk what it could be. I love my 420a DD but it had no power till 4009 rpms till I changed the 02 now it's like it flipped flop.

 

[Chicken Patty]

So is this problem on the TSI or on the 420A?

Do you have a wideband installed on the car?

 

[98talondb]

420a it's my dd

I have a tsi and a 420a n/t dd

 

[Chicken Patty]

420a it's my dd

I have a tsi and a 420a n/t dd

Thanks for clearing that up, post was a bit confusing right at the end for me at least.

Okay, so you said when you changed the O2 it flip flopped? However, under WOT the car does not really rely on the O2 reading to determine how much fuel it needs to dump but instead it relies on a MAP/MAF reading to know how much air is coming in and know what it has to do.

So I would say the O2 is not your main cause to your problem. Have you checked your spark plugs/wires/coil? Maybe time for new fresh set of plugs. If you changed your O2, it might have been because it was faulty I suppose? If so car could have been running rich before and fouled or deteriorated your plugs. On a N/A car, bad ignition can really hurt power, just as it can on any, but when there is not much power there to begin with, it's much more noticeable.

 

[98talondb]

Ok I'll try a diff map sensor tomorow I just put new plugs and wires on it. Before the car would spit and spudder and idle rough till it hit 4k rpms then it would come alive. I put a new o2 on today and it fixed the idle and revs up fine but now there's power loss after 3500 rpms. I guess I'll try the map see if it changes anything. Is there anyway to check to see if it works

 

[Chicken Patty]

Ok I'll try a diff map sensor tomorow I just put new plugs and wires on it. Before the car would spit and spudder and idle rough till it hit 4k rpms then it would come alive. I put a new o2 on today and it fixed the idle and revs up fine but now there's power loss after 3500 rpms. I guess I'll try the map see if it changes anything. Is there anyway to check to see if it works

Off the top of my head I don't know of a way, but I'm sure there's a way to test it by applying voltage or something to it. Should be more info laying around in here.