1999 Volvo S70 EVAP codes

[erikv11]

As per the comments about model year: if those photos are of an S70, then it is a 98. End of discussion!

The codes in the first post suggest two problems overall:

(1) The EVAP codes, the P0455 and P0440, are basically nuisance codes. They may interfere with smog inspections and keep the pesky engine light on, and you will want to fix them, but they are of little consequence in the big picture.

(2) The p0103 and p0172 indicate the ECU is tweaking the air:fuel mixture because it thinks there is a problem. It is probably right and the cause of these codes should be fixed first. Once you have done that, the stalling will likely go away but the EVAP codes will likely remain, the two are unrelated.

The dislodged part in pic 2 is what is called the flame trap housing, it is part of the PCV system. That gap is likely resulting in a leak of unmetered air after the MAF, which could definitely cause a p0172 and p0103. It would not cause EVAP system problems. You need to reseat the flame trap housing. Also carefully inspect the little elbow on the end of the intake manifold, it is a common problem.

[dcmatos]

As per the comments about model year: if those photos are of an S70, then it is a 98. End of discussion!

The codes in the first post suggest two problems overall:

(1) The EVAP codes, the P0455 and P0440, are basically nuisance codes. They may interfere with smog inspections and keep the pesky engine light on, and you will want to fix them, but they are of little consequence in the big picture.

(2) The p0103 and p0172 indicate the ECU is tweaking the air:fuel mixture because it thinks there is a problem. It is probably right and the cause of these codes should be fixed first. Once you have done that, the stalling will likely go away but the EVAP codes will likely remain, the two are unrelated.

The dislodged part in pic 2 is what is called the flame trap housing, it is part of the PCV system. That gap is likely resulting in a leak of unmetered air after the MAF, which could definitely cause a p0172 and p0103. It would not cause EVAP system problems. You need to reseat the flame trap housing. Also carefully inspect the little elbow on the end of the intake manifold, it is a common problem.

I inspected the flame trap housing further and found that not only was it not connected properly, but one of the tubing that leads under the intake manifold has a hole in it. I have not inspected under the intake manifold yet. I assume I can get the replacement tubing from Autozone, so I'll see if they do and keep this updated. I will sideline the p0440 and p0455 issues for the moment if they are not going to be a problem.

[erikv11]

That skinny vacuum line from the flame trap housing goes to the elbow/nipple connection on the passenger side of the intake manifold, the one I keep mentioning.

Lots of pics and info here: https://www.matthewsvolvosite.com/forums ... =1&t=65002

Good chance the car may need a full PCV service soon, but anyway you should be able to sort out those codes fairly quickly.

[dcmatos]

Thank you! This helped me so much! It looks like it would be a PITA to remove the intake manifold, so I will try to route the new vacuum hose above the intake manifold to the IM nipple.

I do think the car needs a full PCV service. Is there a good source for performing a full service on the PCV system?

[RussB]

Your VIN number will tell you what year your car is



PCV info, https://www.matthewsvolvosite.com/forums ... =1&t=28487

[dcmatos]

I'm having an issue gentlemen. I replaced the vacuum hose from the intake manifold nipple to the flame trap housing and is running fine, but I cannot reseat the flame trap housing. It is still dislodged as it is in the first picture that was posted on the first page. It will not seat properly.

[RussB]

Perhaps the flame trap housing is damaged? Flame trap damaged?

[erikv11]

If there is still a flame trap (small plastic disc with holes, or small metal disc with crenulations) inside the housing, then take out the flame trap and throw it away. It does nothing useful.

The housing snaps together by rotation, you insert the male part into the housing then rotate it like 20 degrees to lock it shut. You may have to pull the intake hose to the throttle body to get a good look at it, see the grooves and how it needs to rotate. But like Russ said, the closure on the housing may have worn out by now for various reasons. With a broken one I once cleaned it up and used RTV black to seal it shut, you can always get it open later by peeling it off. But a better solution is to get another one, it is a PITA little part. It is important to not have an air leak there, it will still mess with the air:fuel.

[RussB]

Crenulations


New word of the day!

[abscate]

Crenulations


New word of the day!

Nice....like I had crenulated brûlée for dessert?.