Shudder at 35-45 mph when cold

On my 98 ford taurus with the bad headgasket i have gotten a code (P401) that says something is up with my EGR system. Since that code showed up I have been having the following issue. When i first start the car after it has sat overnight or after sitting at work all day when I take off I feel like a shudder of the engine when I get between 35-45 mph. It only happens once or twice, as once the engine has warmed up i don’t have any issues. Could the EGR problem be the cause of these cool engine shudder?

Yes it could. Have a look at this: http://www.obd-codes.com/p0401 to help you

A lot of the time the passages just need to cleaned of carbon. On Fords the DPFE sensor has been a chronic problem as well.

Thanks for the info, it kinda baffled me since it went away and drives normal (as normal a car can with a bad headgasket) once the eng temp reaches it’s normal operating temp.

This has got to be a record for driving a car with a bad head-gasket,how long has it been in months and miles and what is the longest trip you have made with it? Have you used any magic elixirs such as steel seal or the like and have they helped? How much coolant do you lose a week? Is there any involvement with your oil and have you tried re-torquing your head(s)?

Bought the car back in july of last year, so far have put about 7000 miles on it so far. Longest trip was probably 100-125 miles on a day out trip back in Sept. Haven’t tried the steal seal yet, and I lose about 1 gallon of anti freeze about every 6-7 weeks. Oil is clean as is dip stick, oil has been changed twice since I got the car, it is still getting about 19-20 mpg in the city. i don’t drive it on the freeway, never gotten it above 60 mph at anypoint. Starts fine and engine runs smooth, no smoke (outside normal) out the tail pipe. Had no engine light until this new P401 code. So far I feel that I have gotten my $450 worth.