car started missing

[drewzx3]

Yesterday my car started missing. It misses at idle and wlhen you drive it. Every since I got my chip I was having a problem with the car cutting out every now and then but now it doesnt cut out. When it was cutting out I pulled an EGR code 334 but now it does not pull that code.Spark plugs were replaced about 5 months ago. The car has a month old cap distributor and rotor all from autozone. Where should I start in figuring out my problem?

 

[bill302]

have you pulled the codes since yesterday when it started skipping, if not pull codes and post results.

 

[HISSIN50]

........... and while pulling codes, run a cylinder balance test to narrow down what/which cylinder(s) are acting up.

Good luck.

 

[drewzx3]

Also when I get on the gas pretty hard the tach starts jumping. I am at work right now so I will pull them when I get home.

 

[HISSIN50]

The tach issue, if related, suggests an ignition burp. Narrowing it down between a TFI or coil can be kinda' hit or miss though.

Good luck.

 

[drewzx3]

Well I pulled the same code 334 from the memory codes.

 

[bill302]

it seems you have a problem with either your egr valve or your Egr Valve Position Sensor.
If the pintle position sensor Ford calls it the EVP sensor (egr valve position sensor) is shorted or open, you could have a code set.
If the EGR valve becomes carboned up and does not seat fully, the EVP sensor gives a high reading and a code is set.
If the diaphragm of the EGR valve is bad, then it, too, is flagged.
the EVP sensor (egr valve position sensor) is located at the top of the egr valve click on link for picture of one advance auto parts sells. http://www.partsamerica.com/ProductDetail.aspx?mfrcode=SMP&mfrpartnumber=VP1&parttype=289&ptset=A

 

[drewzx3]

Would that cause it to miss?

 

[drewzx3]

I also pulled code 174.

 

[dstanggt50]

I don't think it would cause it to miss, I've been running a bad evp code for a while, and my car seems to run ok. I don't know what 174 is, but maybe clean the maf? I don't know if the problem is chip related, but maybe take that off and see if anything changes.

 

[HISSIN50]

174 has to do with low O2 switching frequency.