Check engine light?

yes a blocked off egr will cause the check engine light to come on.

Do this. Run the check engine code that its giving you, if you dont know how to buy a chiltons manual from murrays or autozone. This will give you the code and then look it up and it will tell you exactly what it is.

The chiltons only cost around $15 and they pretty much have everything you need to know about your car including the check engine light codes and such.

Also you dont need one of those expensive code checkers either. You can check the codes with an analog voltmeter and a jumper wire for the harness (this is how the chiltons tells you to do it).

Dump the codes and see what the computer says is wrong…

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.dalidesign.com/hbook/eectest.html for more descriptive help
OR
See http://www.mustangworks.com/article...c-iv_codes.html

IF your car is an 88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Walmart .