X_L

My check engine light came on recently and when i had it tested we got code P1491. So i get my EGR Valve replaced and everything cleaned.. a few hours later the CEL light comes back on. I had the code cleared once more and once again it came back on. What more can i do without having to bring it to Acura?! I did a forum search and found some similar problems but didn't find any real answers.


This is extremely frustrating because i have to pass my emissions test this month and it will not pass like this.



edit: info is in the sig.. 96 3.2TL 160,000

01tl4tl

Not sure on your year but the gen2s like to plug up the egr ports in the intake manifold really bad
Even replacing the valve wont help it the pathway is blocked
Check the DIY section for Thermoblock install/ egr cleaning
You have to remove the intake and spray carb clean and a brush thru the holes- that should fix you up and make the car run way better

Its also time for Seafoam treatment to the gas and intake vac line
See gen2 thead, Seafoamed the Ol TL for details- cleans gunk out!! pass smog!!

spooky3ce

1996 has the Emissions recall... Do a search on Emissions Recall and i'm sure you'll find some good info that you might even take it to Acura and get your whole emissions (exhaust/egr/etc...) done for free...

KrayzieDxC

yea but his warranty is already out. they extend to 150k his is 160k..suxs might as well get it clean or diy and take out the intake manifold and clean the hell out of it.. or try seafoam

Go90go

Take off the EGR and spray Intake/Carb cleaner liberally down the tubes. A P1491 is EGR valve insufficient lift, I believe, but I could be wrong. Also, replace your PCV while you're at it, as that could be clogged.

~Cheers~

tnewyes

I got that same code today. After reading your post, I'm not sure if I should replace my egr valve, being as it didn't fix the problem for you. I really don't like spending money for the problem to still exist.

KrayzieDxC

true..

TexasHonda

P1491 says that "insufficient EGR valve lift detected". This means the ECU commanded a certain amount of lift and the feedback transducer on the EGR valve indicates either none or less than commanded occurred.

There are several possible reasons, but blocked EGR ports is not one of them. Following are possible faults:

1) Faulty EGR valve sensor or stuck EGR valve. (You've ruled this one out w/ a new valve.)
2) EGR valve lift sensor circuit (damaged wiring to the EGR valve lift sensor, possible but unlikely).
3) EGR control solenoid -EGR is acutuated by vacuum which is turned on/off by a solenoid valve. If faulty solenoid valve, then EGR won't move. (This is a likely candidate for your fault.)
4) EGR control solenoid valve circuit -damaged wiring to the control solenoid valve (possible but unlikely).
5) EGR vacuum line or control solenoid vacuum supply line damaged or disconnected. Another likely suspect.
6)ECM - possible but highly unlikely.

Check the solenoid valve by applying 12V and listening for a distinct click. If it clicks it's working, if silence a new valve. Check all vacuum lines from EGR to EGR control solenoid for damage or missing lines.

good luck