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The check engine light on my daughter's 2000 S40 is lit. The dealership said it is likely an oxygen sensor. The car has also been stalling intermittently at traffic lights or when generally slowing to a stop.
Assuming the problem is the O2 sensors, how many are there? I just looked under the hood and see what look like 2 before the Catalytic converter and I didn't see any after it (I have not put the car in the air yet for an undercarriage inspection).
I plan to replace them all. How difficult a task is this?
Thanks!
Gary
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There's just the two there... Not at all difficult.
Unscrew, unplug, install new one, plug it in... They have a crush washer with them right?
What are the codes? There shouldn't be a need to replace both.
Get them from FCPgroton, much cheaper than the dealer...
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If you're not driving it "like its stolen," are you really driving?
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OK. I replaced the front sensor since that is the one (bank 1) that showed on the code at the AutoZone (the guys there were super helpful!!!).
Next up is a vacuum leak that is throwing a 'too lean' code and is also (I think) causing the car to stall some times.
I bought the OBDII diagnostic sensor because I don't want to be beholden to the guys at the dealership to tell me what is wrong with the car. It is my daughter's car so it has to be reliable.
Gary
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Get the leak under control soon. A car running rich will fry the O2 sensor, then the CAT... The expenses will add up quick... Start with the obvious lines and connectors, move to the other components (such as fuel pressure), then consider a smoke test (there's a good DIY link on here somewhere..). Lean isn't as dangerous, but with vacuum leaks its possible for it to go either way...
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If you're not driving it "like its stolen," are you really driving?
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I just reviewed and cleared all codes using my OBDII scanner device. There were basically 3 different codes that were repeated a few times each. I changed the front O2 sensor so am not worried about those anymore. There were a couple of instances of turbo overboost, which I assumed to mean a vacuum leak. As indicated by me previously, we had a problem in that the air intake hose was loose, thus causing the car to die and the brakes to function poorly. I am going to assume for now that this was my "vacuum leak." The other gave me the impression that it is an issue with the mass airflow sensor. However, after reading posts on other sites for a similar stalling issue, I am inclined to believe that it is an idle control sensor.
At any rate, I have erased all codes so I can start with a baseline and will work forward from here. Cross fingers, but I think the only remaining issue may be the idle control sensor. If I continue to get the aforementioned code, that is the part that will be on my hit list.
I will provide updates as they occur. Thanks for your help!
Gary
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Was your air intake loose before or after the MAF, if before, than there shouldn't have been any issue. If after, then there's your problem...
Good luck!
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If you're not driving it "like its stolen," are you really driving?
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Well, that wasn't it because Last Monday night at dinner, my daughter reported that the Check Engine light was back on.
So I connected my scanner to it yesterday and found the codes mentioned in my previous post: P0234 turbo overboost, P0171 Bank 1 system too lean, and P0101 mass or volume air flow A circuit range/performance.
I cleaned the MAF and, while waiting for it to dry, noticed that a hose below the radiator hose (I believe it is the PCV hose that runs from the grill back to the engine in an S-shape) was broken off at the engine. I got a piece of radiator hose of similar diameter and clamped it in place.
It has been 1 day and, knock wood, so far so good. The car was stalling before when I rapped on and off the accelerator while in park. Now it reverts to a smooth idle.
Does this make sense or am I just going to be disappointed in a day or two when the symptoms reappear?
Thanks!
Gary
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Yep, makes tons of sense. The engine assumes many things that are always correct, and when they're not it screws up. Fuel delivery, the vacuum system, and a few others are unmonitored systems that are 'always working' according to the computers calculations. Break a hose off and you'll get problems... That hose affects the turbo too, which can set off that code. Odds are you'll be good. A thorough investigation of vacuum lines (and replacement of shifty looking ones) might be good for the car. The hoses and connectors tend to last 5-10 years before age wears them out. Perhaps next spring (assuming its fixed now) when its warm again, you might want to check them all, and replace many of them..
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If you're not driving it "like its stolen," are you really driving?
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That makes sense. I always assume that the engine has processors monitoring everything and scratch my head when something like this slips through the cracks. Why didn't it compensate?
I need to find a good repair manual (one with lots of pictures) so I'll know what I'm messing with in the future. Do you have a preferred manual or manual series (e.g. Chilton's, Haynes, etc.)?
It is (nearly) always warm where I live (North Carolina). I just need to get a manual, summon my courage and dive in.
Thanks for your help!
Gary
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posted by
someone claiming to be AyUaxe
on
Mon Oct 25 05:40 CST 2010 [ RELATED]
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We've had an '00 S4 since new and she's still ticking. On the brake/vacuum issue, please check to see if there is a vacuum pump located in the left (driver's side) fender well (forward of the tire). That's where they were from the factory and they and connected hoses failed often and with pretty disconcerting results if you were cruising at highway speeds and needed to stop (from personal, thank God, non-tragic experience). You will hear it running at start up when the engine is cold. There was a recall whereby the vacuum pump was relocated to a more protected location in the engine compartment. It is barely audible, if at all, in my experience. Be sure, for your kid's safety, that the recall work was done.
Haynes manual from the UK is the only manual for this car I have ever heard of or seen. It's barely adequate for most "shade tree" tasks. You can order from Amazon UK or other UK online bookseller, I think. That's how I got mine. There is great info on this forum and on other Volvo sites, like Volvospeed (look for Bay 13), and Matthew's Volvo site. Sorry, I don't have the links handy, but google and this forum are your best friends. You'll find that there is a remarkable similarity between the mechanics of the 1st gen. s40 and later 850s--just one less cylinder and less room to move around the engine.
Expect short headlight life and rear brake pad life. The former is a glitch that another recall (some different wiring harness parts--I never dug into exactly what it was) did not fix on my car. The latter is due to brake pressure balancing which shifts more braking to the rear than most cars would--it makes the car very safe and stable in hard braking, but eats the too-little rear pads. I got about 12k miles out of oem pads and maybe 50% more out of good quality aftermarkets (mintex). Intended to try EBC green or red stuff, but just never have--cost was an issue.
As said, we've had her since new--considered getting rid of her a few times, but never found anything we really wanted enough more to pay for it. She's got character, nice performance and reasonable durability. Hope your daughter enjoys hers as much as we've enjoyed ours.
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I have yet to find a good manual to show vacuum routing, let alone enough pictures for my liking. I've found that the best way to do it (although its not a quick way) is to take pictures and go one (or two) at a time, always making sure you know where every hose goes.. Some painters tape (i always have some lying around the garage it seems, perhaps its from the painting I should be doing...) marking the new ones helps you from doing the hose twice, and its not hard to remove (or really matter if you don't).
It will compensate to a point, but with a hose broken off the block like that you get multiple points of failure. Air seeps into the block, and air seeps into the hose (or out of either or both points, it can change the amount as it sees fit..) and gets into the engine. The fuel trim will only compensate so much before the codes go off blaming some component.
To monitor all the systems would almost double the sensors on the car. Which would increase the price of the car, significantly. Its not really a bad thing to always assume that a component is working (or always not working..) like a fuel pump. There's not really a need to put a sensor on it, if it works you get fuel, and if it doesn't you don't. It doesn't really degrade performance like many other components, which makes diagnosis easier. They also assume you do routine maintenance (I'm not saying its impossible to clog a fuel line if you change your fuel filter every year, and only get good gasoline, but its quite unlikely). There's just little to be gained in the operation of the car compared to the cost of implementing the system. Another problem is you'd have to find a way to avoid false positives, and to be honest, it'd be a nightmare.
I was lucky enough to make friends with a parts guy who 'loaned' me a copy of Vadis that they had no use for.. But I've got a haynes and a Chilton. Add those three in with the site and I can usually figure out what to do. I think a lot of the things that aren't covered, aren't covered because the components vary too much for the car, so rather than having 5 different instructions based on which model, they just leave it out... BTW, last I checked you could find Vadis on ebay for <100. Its probably just as shady as the copy I have, but if it works it works, right?
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If you're not driving it "like its stolen," are you really driving?
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