If it feels like its choked up when trying to move off from stopped then I would have a look at the O2 sensor, when they get old and covered in carbon deposits they tend to think that the engine is running rich. As a result, you'll be getting less fuel into the engine and you'll be experiencing a lean misfire (feels like the fuel isn't getting through, which is what is happening).

It helps if the car has a post cat lambda as well, because when this was happening on a new clio I looked at (emissions light was on but EML wasn't) the lambda looked like it was working fine, but the post cat was indicating that the engine was running far too lean. New lambda fixed the problem instantly.

ECU wasn't picking up a fault because it beleived the Lambda was working right. A cheap code reader will show this and will save a lot of money in the long run (MAFs, Plugs and coil packs cost most than most code readers!).