I have 2.  The first is easy P0135-O2 sensor.  The next is p0400.  It said egr flow failure on my scanner.  Does this mean I replace the egr or just check all the lines going to it and replace one or more that are leaking???  Just trying to be as lazy as possible so thanks
Brian

clean the EGR and the carbon buildup in the crossover passage in the head

well that's not lazy
Brian

Using a can of spray cleaner 

You don't say what engine, so I'm guessing '96+1.6 16v... po135 is front o2 sensor heater circuit, can't be repaired, buy a new sensor & replace it. Bosch has a plug & play with the proper 4wire connector. Just be careful removing the old 1 so you don't crack you manifold.
po400 is low EGR flow... most times it can be cured by cleaning the port into the intake plenum & the tube that feeds it from the EGR main. Here's a good pic of the port to clean, looking into the TB from drivers side (1/2 way down page):

http://www.kick-fix.com/EGR-horror2.html

Hth,
Fuzz

That's the best answer I have ever seen in my life... wow   Thanks for your time
Brian
ps
Hey Eric, I got a new trackick