Good afternoon everyone,

Let me start by giving you some background. In October, My brake booster went out and near the same time a code P0172 came up, which I assumed to be a vac leak from the booster, which was making a hissing noise from the petal. I replaced the booster last week, I know a long time to go without brakes hardly, but I only drove the car 3-4 days a month, so no big deal. Now I drive it daily, so we got it fixed. I bought a code scanner to erase what I thought was the only code, turned out he had 3 friends with him, erased all the codes, they all came back. I have four codes here, P0172, P0300, P0303, P0410. Not to mention my measley 8-12 MPG I have been getting since last year. I am about to replace the plugs and see what that does, but what else are we looking at here? The P0410 is scaring me a bit. Well, let me know guys, you got me back on the road before, lets try again...

Thanks for any help you can contribute...

 

What year and model is the car?

You have a missfire that will cause alot of them to come up.
Replace Dist. cap,rotor,wires and plugs.

Most likely that will cure the problem.

 

OOPS! sorry, forgot the pertinant information didn't I? I have a 1996 960 Sedan.

I cleared the codes out after I did the plugs awhile ago, no codes as of yet, went and drove it almost 95 miles, and still nothing, however on my code scanner, it I guess is showing an open cycle and wont read the codes until it closes, how long does this usually take? I am coming down to the deadline for emissions here in Georgia and need to get this all figured out soon, lol. Thanks for the help so far, I'll take anymore I can get though.

Thanks,

Timothy

 

It should have been done already.
The scanner should have also checked for codes no problem.
I have never seen a scanner that won't read the codes because the Self Diag wasn't done.

 

yep, no codes, so i tried emissions today & failed because the obd2 is in an open cycle. Georgia's emission system will not allow the test to complete and will automatically fail any vehicle where the obd2 is in an open cycle. So it sounds like I'll have to wait until it resets itself to try again, oh well lost 25 bucks but at least the retest is free. So I am assuming that there is no way to manually reset the obd2 system?

Thanks.

 

NO it has to go through a specific driving cycle to close.
But it may take a couple of days or even a week.

 

Alright, yeah, I talked to another volvo teckie today and he said 4-5 driving cycles of at least 35 mph with a cool off period in between. Thanks for the new info. Hopefully I'll get that done in the next day or so, but chances are, the damn C.E.L. will probably come back on, but let's hope for the best...

Once again thanks,

Timothy

 

Im praying for you let us know how you make out.

 

Every monitor has it's own set of perameters that the vehicle must meet in order to run it's self tests. Once the monitor has run, the statis changes from "not ready" to "ready" regardless of whether or not the test past or failed. Meeting the set perameters for induvidual monitors (drive cycles) can be difficult to perform, but for most vehicles it is fairly simple. Hopefully the drive cycle your contact gave you works. If not, I can look it up for you. Good luck

 

you need to let all the monitors finish their cycle, you could theoretically do it in hour and half by following a protocol, but driving the car during a week usually does it... check all the vaccum lines, plugs, filter, coil for any cracks... I did it all and had a P0172 code keep coming up... brought to volvo dealer who tested everything and suggested the maf was reading a low value(i had a used maf that gave the same low reading, hard to believe 2 mafs going bad!) The o2 sensor was also good...After a month on my own, i discovered the problem! The themostat that controls the airflow, from front of car vs. exhast manifold area, via a duct flap was broken...I had a renault R-10 that i could shift warm air in winter from exhaust manifold to cooler air during summer manually. Any way since i live in california, i drywall screwed the flap to only divert cooler air to the air filter and then on to the MAF! NO more check engine light! I would like the TECH moderator comment on my current problem, 96 960 occasionally loses rpms or power on the freeway, but will accelerate if i hit the pedal and again will operate normally. Occasionally, it will run rough at idle and stall out, but start immediately without a persistant problem. No check engine light comes on! I've checked for vaccum leaks, cleaned throttle body, used premium gas,etc. the only other thing is that when i accelerate the a.c. fans shut down then normalize at steady state speed. help and thanks